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[Display omitted] • CuFe 2 O 4 catalyst with (111) dominant facet was prepared by KNO 3 as capping agent. • (111) facet has lower hydrolytic ionization barrier and suitable *H binding strength. • Performance of the electrode was further improved by making into 3D printed electrode. • The 3D printed electrode has more exposed active sites and fewer phase interfaces. • 3D (111) CuFe 2 O 4 electrode is only 160 mV at 100 mA cm−2, Tafel slope is 33 mV dec-1. The utilization of hydrogen energy is an important way to low carbon economy, and the development of active electrodes is the most critical step for efficient hydrogen evolution reaction. With the addition of KNO 3 as a capping agent, the exposed crystal facet of CuFe 2 O 4 is regulated, and the crystal facet (111) becomes dominant. Compared to CuFe 2 O 4 (3 1 1), CuFe 2 O 4 (111) exhibits low barrier of water dissociation and suitable *H binding strength, resulting in high intrinsic activity. Furthermore, the 3D printed electrodes show more excellent performance. At 3D printed CuFe 2 O 4 (111) electrode, the overpotential is only 152 mV (vs. reversible hydrogen electrode) at 100 mA cm−2, and Tafel slope is as low as 33 mV dec-1. In addition, 3D printed CuFe 2 O 4 (111) electrodes shows high stability. The superior performance of 3D printed CuFe 2 O 4 (111) electrodes originates from high intrinsic activity and more exposed active sites. This study provides a new path for the development of efficient, stable and inexpensive monolithic catalyst electrodes for alkaline hydrogen evolution. [ABSTRACT FROM AUTHOR]

[Display omitted] • Heterostructure Ni 2 P/Ni 12 P 5 is rationally fabricated via a facile solution combustion route. • Heterostructure and defective substrate benefit the optimized electric field and electron transfer. • The optimal catalyst exhibits a low potential of 1.32 V@100 mA cm−2 and a Tafel slope of 31.4 mV dec−1 in UOR. • The heterostructure enhances the adsorption of the reaction intermediate by redistributing the interfacial charge. Developing efficient electrocatalysts and investigating catalytic mechanisms are crucial in urea oxidation reaction (UOR) as a promising strategy to boost the energy efficiency of hybrid water electrolysis for H 2 production. The present work rationally designed and fabricated Ni 2 P-Ni 12 P 5 heterostructure with varying relative ratios embedded on the defective carbon–nitrogen-phosphorus substrate (Ni 2 P-Ni 12 P 5 /CNP) for high-performance UOR in alkaline conditions through a facile solution-combustion route without extra phosphorus sources. The developed synthesis method avoids the high cost, complicated routes, and extremely toxic emissions. Experimental and theoretical studies demonstrated that the Ni 2 P-Ni 12 P 5 heterostructure regulated the interfacial electric field and promoted electron transfer. The abundantly defective CNP substrate improved the electrical conductivity and prevented Ni 2 P-Ni 12 P 5 heterostructure from corrosion and detachment. The optimal electrocatalyst, with an approximately equal content of Ni 2 P and Ni 12 P 5 , exhibits a low potential of 1.32 V to deliver 100 mA cm−2, a small Tafel slope of 31.4 mV dec−1, robust stability of 80 h in UOR, and a low voltage of 1.85 V to reach 100 mA cm−2 in HER||UOR. This work provides a facile route to design electrocatalysts for efficient electrochemical hydrogen production. [ABSTRACT FROM AUTHOR]

[Display omitted] • The C-doped supramolecular preassembly strategy introduces N defects. • The s-B 0.3 CN shows effective performance in generating H 2 O 2 and degrading 4-CP. • The dual-channel photocatalytic H 2 O 2 evolution was demonstrated. The synthesis of hydrogen peroxide from photocatalytic reaction of pure water and oxygen has sparked extensive research, however, most photocatalysts have weak light absorption and fast carrier recombination rates. Herein, a C-doped graphitic carbon nitride g-C 3 N 4 with defects (N vacancies and -C≡N groups) was prepared using a supramolecular preassembly method. The as-prepared photocatalyst (s-B 0.3 CN) exhibited good H 2 O 2 generation performance (108.4 μM under λ ≥ 420 nm in pure water, 2 h) and efficient degradation of 4-CP in a photocatalysis-self-Fenton process. The structure formed by the C-doped and defects significantly facilitated light absorption and carrier separation, increased the specific surface area of the material and enhanced the adsorption of oxygen. Furthermore, this research contributes the understanding of the mechanisms about photocatalytic H 2 O 2 evolution and photocatalysis-self-Fenton. Simultaneously, dual-channel photocatalytic H 2 O 2 evolution mechanisms (O 2 + 2e- + 2H+→ H 2 O 2 ，2H 2 O + 2 h+ →H 2 O 2 + 2H+) of s-B 0.3 CN under irradiation were demonstrated. [ABSTRACT FROM AUTHOR]

[Display omitted] • A high-performance Ru-Ni 3 S 2 /Ni x P y catalyst was fabricated. • Synergy of dopant and interface induced an ultrastrong electronic coupling. • Ultrastrong coupling effectively regulated the surface electronic structure. It is challenging to fabricate high-efficiency and low-cost bifunctional electrocatalysts for water splitting. Herein, a high-performance nickel-based catalyst, Ru-Ni 3 S 2 /Ni x P y , was constructed via heteroatom doping and interface engineering. The synergy of Ru-doping and sulfide-phosphide heterointerfaces induced the ultrastrong electronic coupling on the catalyst surface, which effectively regulated electronic densities of the catalyst, improved intrinsic catalytic activities, and resulted in the excellent HER and OER bifunctional performances. In alkaline medium, it only required the OER overpotential of 244 mV for the as-prepared Ru-Ni 3 S 2 /Ni x P y catalyst to achieve 100 mA∙cm−2 and the HER overpotential of 51 mV to reach 10 mA∙cm−2. And only a voltage of 1.46 V was required to generate 10 mA∙cm−2 in the Ru-Ni 3 S 2 /Ni x P y (+,-) cell. Furthermore, the as-prepared Ru-Ni 3 S 2 /Ni x P y catalyst exhibited a long-term durability for water splitting. The DFT calculations indicated that the ultrastrong electronic coupling was primarily attributed to the aggregation of electrons around heterointerfaces and the excellent catalytic performance was due to effectively adjusting the adsorption of intermediates on active sites. This work is helpful for developing an effective strategy to fabricate high-performance catalysts. [ABSTRACT FROM AUTHOR]

Cocatalyst modification of photocatalysts is an important strategy to enhance the photocatalytic performance by promoting effective separation of photoinduced electron-hole pairs and providing abundant active sites. In this study, a facile in situ photodeposition method was developed to prepare amorphous CoS x -modified TiO 2 photocatalysts. It was found that amorphous CoS x nanoparticles were solidly loaded on the TiO 2 surface, resulting in a greatly improved photocatalytic H 2 -evolution performance. When the amount of amorphous CoS x was 10 wt%, the hydrogen evolution rate of the CoS x /TiO 2 reached 119.7 μmol h −1 , which was almost 16.7 times that of the pure TiO 2 . According to the above experimental results, a reasonable mechanism of improved photocatalytic performance is proposed for the CoS x /TiO 2 photocatalysts, namely, the photogenerated electrons of TiO 2 can rapidly transfer to amorphous CoS x nanoparticles due to the solid contact between them, and then amorphous CoS x can provide plenty of sulfur active sites to rapidly adsorb protons from solution to produce hydrogen by the photogenerated electrons. Considering the facile synthesis method, the present cheap and highly efficient amorphous CoS x -modified TiO 2 photocatalysts would have great potential for practical use in photocatalytic H 2 production. [ABSTRACT FROM AUTHOR]

Transition-metal selenides have been regarded as promising anode materials for energy storage and conversion fields. However, their practical application is hindered by volume expansion, polyselenide dissolution, and sluggish kinetics. Herein, porous Fe 3 Se 4 rice grains were successfully encapsulated on cotton derived carbon network (CN@Fe 3 Se 4 @C) by facile solvothermal method combined with in-situ selenization process. Beneficial from the unique structure, the CN@Fe 3 Se 4 @C electrode exhibits excellent sodium storage properties (302 mAh g−1 at 500 mA g−1 after 500 cycles) and hydrogen evolution reactions (HER) performance (an overpotential of 168 mV at a current density of 10 mA cm−2, and a low Tafel slope of 77 mV dec−1). Electrochemical mechanism investigations demonstrate that the carbon coated porous Fe 3 Se 4 nanoparticles and ant nest-like carbon network can shorten the diffusion path for Na+ ions and suppress volume expansion. Meanwhile, the 3D interconnected porous carbon framework can provide multiple channels for fast electron transport and improve electron conductivity. In addition, the thin amorphous carbon layers on individual Fe 3 Se 4 rice grains can well inhibit the shuttle effect of polysulfides and the agglomeration of Fe 3 Se 4 , ensuring fast kinetics and long-term stability. This study reveals the great potential of CN@Fe 3 Se 4 @C as active materials for sodium ion batteries and hydrogen production. [Display omitted] • Porous Fe 3 Se 4 rice grains are encapsulated in cotton derived carbon framework. • Nest-like carbon matrix possesses robust structural strength and fast electrons transportations. • The CN@Fe 3 Se 4 @C shows superior Na+ storage properties and catalytic activity. [ABSTRACT FROM AUTHOR]

Se and Fe co-doped Ni 2 P/Ni 12 P 5 /NF result in excellent OER electrocatalytic performance and ultra-long stability. [Display omitted] • A new Se, Fe co-doped Ni 2 P/Ni 12 P 5 /NF nanoparticle was synthesized. • It exhibits good OER electrocatalytic performance and ultra-long stability (at least 100 h). • The co-doping of Se and Fe can effectively reduce the energy barrier of electrocatalytic reactions and improve the morphology, which is responsible for the high activity and ultra-long stability of the catalyst. Hydrogen production by water splitting is a promising hydrogen production technology, but limited by the slow OER reaction kinetics, the development of high-performance OER catalysts is urgently needed. Herein, a three-step process of hydrothermal, electrodeposition and phosphorization was carried out to grow nanoparticulate Se, Fe-Ni 2 P/Ni 12 P 5 on NF (Se, Fe-NiP/NF) in this work. The catalyst exhibits excellent OER electrocatalytic performance, requiring an overpotential of only 225 mV to achieve a current density of 10 mA·cm−2 with a Tafel slope of only 33 mV · dec−1, and can maintain stability for more than 100 h under alkaline conditions. Remarkably, the surface of the nanoparticles after stability testing was rougher, exposing many very small nanoflakes thus exposing more active sites, which is responsible for its extremely long time stability. The results show that the co-doping of Se and Fe can effectively reduce the energy barrier of electrocatalytic reactions and improve the morphology, which provides a new approach to explore high-performance and corrosion-resistant electrocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hollow nanocages constructed by anion exchange benefit the abundance of active sites and mass and charge transportation. • The formation of CoMoO 4 enhances the thermal stability of the composite. • The introduction of Mo improves the conductivity of the composite. • The interfacial electron transfer between Co 3 O 4 and CoMoO 4 facilitates the electrocatalytic OER activity of Co site. Hollow nanocages composed of heterostructures play an important role in oxygen evolution reaction (OER) due to their high electrocatalytic activity induced by the interfacial polarization within the interface of the heterostructure. In this work, ZIF-67 was used to synthesize Co 3 O 4 /CoMoO 4 hollow nanocages (Co 3 O 4 /CoMoO 4 HNC). Transmission electron microscopy (TEM) images verify that Co 3 O 4 /CoMoO 4 HNC was composed of Co 3 O 4 /CoMoO 4 heterostructures. X-ray photoelectron spectroscopic (XPS) characterizations show that the Mo 3d peaks of Co 3 O 4 /CoMoO 4 are located at lower binding energy compared with CoMoO 4 , indicating charge transfer between Co 3 O 4 and CoMoO 4. The electrochemical studies show that Co 3 O 4 /CoMoO 4 HNC exhibited excellent OER activity in an alkaline medium with only 248 mV overpotential required to achieve a current density of 10 mA cm−2. Co 3 O 4 /CoMoO 4 HNC was tested as the anode material in a homemade water-splitting device to produce oxygen. The Co 3 O 4 /CoMoO 4 HNC‖20 % Pt/C electrolytic cell shows equivalent performance to RuO 2 ‖20 % Pt/C cell at 50 °C. The excellent OER performance of Co 3 O 4 /CoMoO 4 HNC is attributed to the interfacial charge transfer between Co 3 O 4 and CoMoO 4 which promote the adsorption of OH−. Besides, the hollow nanocage structures provide a large surface area, leading to more active sites for OER. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel 0D/2D MoS 3 QDs/C-doped atomic-layer TiO 2 (B) nanosheet composite was fabricated. • The unique nanostructure exhibits remarkable performance for photocatalytic H 2 evolution. • MoS 3 exhibits a superior cocatalyst than MoS 2 and Pt for H 2 evolution and stability. Developing efficient photocatalysts for H 2 generation is of huge interest for sources of long-term sustainable energy. Here, a novel 0D/2D MoS 3 quantum dots (QDs)/C-doped atomically thin TiO 2 (B) nanosheet composite (MoS 3 /TiO 2 (B)-C) was fabricated for H 2 evolution. The simultaneous loading of the highly-efficient cocatalyst MoS 3 and carbon and oxygen vacancy co-doping into an atomically thin TiO 2 (B) nanosheet was achieved by an annealing process. This unique nanostructure of the MoS 3 /TiO 2 (B)-C exhibits remarkable photocatalysis of H 2 in the full spectrum. We obtain a yield of 2.47 mmol·g−1·h−1, 30 times higher than pure TiO 2 (B) nanosheet, and even higher than MoS 2 and Pt loaded TiO 2 (B) nanosheets (2.23 and 2.36 mmol·g−1·h−1, respectively). In-depth characterization shows that notably MoS 3 is a superior cocatalyst than MoS 2 for H 2 evolution and stability. We note MoS 2 is an earth-abundant robust cocatalyst previously recognized as an ideal substitute for Pt. Importantly, this research work also provides new insights for the design and practical manufacture of low-cost highly efficient H 2 generating photocatalysts by ultra-thin 2D materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • The NiMo@C sample was prepared by using an in-situ growth strategy. • The NiMo@C sample exhibits high HER and OER activities. • The NiMo@C sample exhibits outstanding catalytic durability. Reasonable interface regulation is a promising way to obtain bifunctional or multi-functional catalysts as the heterogeneous interface generally offers unique electronic structures. Here, we design a strongly coupled interface structure in Ni 3 Mo 3 N/Mo 2 C coated with graphitized carbon (Ni 3 Mo 3 N/Mo 2 C@C) by using an in-situ growth strategy. The density functional theory calculation unveil that the heterointerface of Ni 3 Mo 3 N/Mo 2 C@C not only facilitates the charge transfer, but also regulates the adsorption free-energies of the reaction intermediates (*O, *OH, and *OOH), to achieve superior electrocatalytic performances for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). As bifunctional catalysts, the Ni 3 Mo 3 N/Mo 2 C@C exhibits high HER and OER activities, with 43 mV and 220 mV overpotentials at the current density of 10 mA cm−2 in 1 M KOH electrolyte, respectively, as well as outstanding catalytic durability. This interface coupling strategy may provide a useful path to promote the electrocatalytic activities for diverse reactions in the energy field. [ABSTRACT FROM AUTHOR]

[Display omitted] • A promising low-cost and efficient single-atom catalyst on VSe 2 monolayer for NRR has been found. • W-VSe 2 with good stability has a limiting potential of −0.36 V through distal mechanism. • Total magnetic moment of TM-VSe 2 was identified as a descriptor for NRR catalytic activity. • The intrinsic features of active SACs for NRR have been proposed. There has been an increasing interest in converting nitrogen (N 2) to ammonia (NH 3) via electrochemical nitrogen reduction reaction (NRR). In this study, the NRR catalytic performance of a series of single transition metal (TM) atoms anchored on two dimensional VSe 2 (TM-VSe 2) was studied via performing the first-principles calculations. Among the investigated single-atom catalyst of TM-VSe 2 , W-VSe 2 demonstrates the best NRR catalytic performance with a limiting potential of −0.36 V and effective inhibition of the competitive hydrogen evolution reaction. Meanwhile, our calculations demonstrate that W-VSe 2 is highly stable as single-atom anchored on the surface of VSe 2 monolayer, whose improved electrical conductivity ensures the electron transform during NRR process. Moreover, we found that the limiting potential of NRR on TM-VSe 2 was negatively correlated with the adsorption energy of reaction intermediate *N-NH, and related with the total magnetic moment of TM-VSe 2. Importantly, we identified the origin of the NRR catalytic activity from electronic aspect. Our results provide a new way for measuring the NRR catalytic activity of single-atom catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel Ti 0.5 Ru 0.5 O 2 /TiO 2 (B)/TiO 2 (A) nanosheets are constructed. • The nanosheets exhibits a remarkable photothermal synergistic H 2 evolution rate. • Ti 0.5 Ru 0.5 O 2 shows much better co-catalytic ability compared to Ru and RuO 2. TiO 2 is an important material used in photocatalytic H 2 evolution. Here nanosheets with a Ti 0.5 Ru 0.5 O 2 /TiO 2 (B)/TiO 2 (A) three-phase-junctions, composed of solid solution rutile phase Ti 0.5 Ru 0.5 O 2 , bronze phase TiO 2 (B), and anatase phase TiO 2 (A), are constructed via a hydrothermal method and subsequent calcination. At the optimal calcination temperature of 350 °C, the highest H 2 evolution rate reaches 27.817 mmol∙g−1∙h−1 at 25 °C, which is further increased up to 62.357 mmol∙g−1∙h−1 at 70 °C by synergistic photothermal catalysis. The photocatalytic activity of the optimized catalyst was further enhanced by loading with Pt as a co-catalyst. It is found that, in addition to helping charge separation, migration, and inhibiting the charge recombination, the three-phase-junctions structure is a key to present strong oxidation and reduction ability. Ti 0.5 Ru 0.5 O 2 solid solution has excellent co-catalytic ability, much better than Ru oxide, metallic Ru, as well as Pt. It works as hole acceptor, accelerating the generation and quench of photo induced peroxyl radicals, and thus significantly enhancing the H 2 generation rate. [ABSTRACT FROM AUTHOR]

• Improve the electric conductivity of the MoS 2 by Cu dopant. • Realize the phase transition of MoS 2 from 2H phase to 1T phase by Pd dopant. • Increase active site density via synergistic effects of Cu and Pd doping. • Improve HER intrinsic activity of MoS 2 via synergistic effects. Molybdenum disulfide (MoS 2) is reckoned as one of the most positive low-cost HER catalysts to replace platinum-based precious metals in acid media. Unfortunately, some issues preclude MoS 2 from being truly applicable including limited active sites, poor conductivity and lack of intrinsic activity. Herein, we report a Cu, Pd co-doped MoS 2 nanomaterial as an efficient and stable HER electrocatalysts, which partially resolve the above-mentioned problems and leads to high overall performance. Specifically, we improve the electric conductivity of the MoS 2 by Cu dopant and realize the phase transition of MoS 2 from pristine 2H phase to stable 1T phase by Pd dopant. More importantly, we increase active site density to facilitate fast electrocatalytic Faradaic process via synergistic effects of Cu and Pd doping, and tune electronic energy states of MoS 2 to improve HER intrinsic activity. In acidic media, the performance of Cu-Pd-MoS 2 catalyst in terms of a low overpotential (−93 mV) at 10 mA cm−2, a small Tafel slope of 77 mV dec−1, and an excellent stability is better than that of single-doped catalysts. [ABSTRACT FROM AUTHOR]

• Poto-deposited Hexagonal CdS/TiO 2 (B) shows visible light catalytic activity. • Hydrothermal fabricated Cubic CdS/TiO 2 (B) shows only UV light catalytic activity. • The photocorrosion resistance of CdS/TiO 2 (B) can be enhanced by PVP modification. A conventional TiO 2 photocatalyst cannot respond to visible light due to its large band gap. Here, we describe the construction of tandem CdS/TiO 2 (B) nanosheet architectures with visible light H 2 evolution. A type II heterojunction of hexagonal CdS/TiO 2 (B) (PCT) was constructed by photodeposition and CdS dots, with size about 6 nm, were anchored on TiO 2 (B) nanosheets. A second type I heterojunction of cubic CdS/TiO 2 (B) (HCT) was fabricated by a hydrothermal method and CdS nanoparticles, with size about 50 nm, were dispersed on TiO 2 (B) nanosheets. Both heterojunction systems display remarkable enhancement of H 2 evolution activity under full spectrum irradiation, with highest H 2 evolution rate of 1776 μmol·g−1·h−1 for the photodeposited catalyst and 1494 μmol·g−1·h−1 for the hydrothermal process. The different heterojunction systems show very different H 2 evolution under just visible light irradiation. The highest H 2 evolution (1577 μmol·g−1·h−1) for the type II system is far much higher than the type I (48 μmol·g−1·h−1). The type II system shows more effective utilization of full spectrum with the apparent quantum efficiency in the wavelength range extended from 300 to 500 nm, matching well with the optical absorbance spectrum of the composite catalyst. The structure, morphology, and photocatalytic mechanism of the CdS/TiO 2 (B) composites are discussed. [ABSTRACT FROM AUTHOR]

• One step hydrothermal synthesis of Co-doped ternary alloy of MoS 1+X Se 1+Y. • The most promising cobalt/molybdenum atomic ratio catalysts were discussed. • Co-MoS 1+X Se 1+Y 1-5 demonstrates the outstanding overall water splitting electrocatalysis. The electrocatalytic overall water splitting is currently regarded as an efficient method for reservation and conversion of sustainable energy sources. The earth-abundant transition-metal chalcogenides (TMCs) possess unique properties to realize hydrogen evolution reaction (HER), but the semiconductor 2H phase behaves a medial activity for HER and even worse performance for oxygen evolution reaction (OER). To date, developing the efficient and bifunctional TMCs electrocatalyst is an attractive but difficult task. Herein, Co-doped 1T′/T phase dominated MoS 1+X Se 1+Y alloy (Co-MoS 1+X Se 1+Y) nanosheets electrocatalysts were synthesized by a one-step facial hydrothermal method. Meanwhile, the crystal structures and element composition of the Co-MoS 1+X Se 1+Y were determined by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Importantly, the as-prepared catalysts Co-MoS 1+X Se 1+Y with the atomic ratio of Co: Mo = 1: 5 (Co-MoS 1+X Se 1+Y 1-5) shows superior electrochemical activity, achieving current density (j) of 10 mA cm−2 at small overpotentials of 119 mV and 280 mV for HER and OER in 1.0 M KOH, respectively. Moreover, applying the bifunctional electrode in an alkaline water electrolytic cell allows a high-efficiency electrocatalyst with only 1.60 V at j = 10 mA cm−2, which could be practical in electrocatalytic overall water splitting reaction devices. [ABSTRACT FROM AUTHOR]

Schematic mechanism of photocatalytic H 2 evolution over Pt/HTi 2 NbO 7 nanosheets. • Pt/HTi 2 NbO 7 nanosheets are prepared by different strategies. • Pt/HTi 2 NbO 7 nanosheets via photoreduction exhibits enhanced H 2 evolution activity. • The Pt nanoclusters on the nanosheets effectively improve the photogenerated charge separation. • The synergistic effect between Pt and the nanosheets greatly enhance the hydrogen evolution. Photocatalytic hydrogen production, as an ideal strategy for solar-to-fuel conversion, remains the great challenges in designing the highly efficient photocatalytic systems. Herein, the monolayer HTi 2 NbO 7 nanosheets with the thickness of 1.65 nm are developed as photocatalysts coupled with Pt nanoparticles for hydrogen production from water. The Pt nanocluster/HTi 2 NbO 7 nanosheets prepared via an in situ process showed the better photocatalytic activity for H 2 evolution than that obtained by a chemical reduction. The higher dispersity and more closely interface contact between the nanosheets and Pt nanoclusters would promote the transfer of the photogenerated carriers. A synergistic photocatalytic mechanism for monolayer nanosheets and Pt nanocluster would be proposed to elucidate the high efficient hydrogen production. [ABSTRACT FROM AUTHOR]

• 0D/2D Ni 2 P quantum dots/TiO 2 (B) nanosheets architecture was synthesized by a solvothermal method. • Photocatalytic H 2 evolution rate is superior to the noble metal Pt as cocatalyst. • The quantum efficiency of 10% Ni 2 P/TiO 2 (B) nanosheets is as high as 31% at 313 nm. • The H 2 production can be further enhanced 5 times by photothermal synergistic reaction at 90 °C. The development of low cost, stable, robust photocatalysts to convert solar energy into hydrogen energy is an important challenge. Here, we describe a simple solvothermal method to successfully fabricate a catalyst with a hybrid 0D/2D Ni 2 P quantum dot/TiO 2 (B) nanosheet architecture. HRTEM shows that Ni 2 P quantum dots about 5 nm in size were dispersed on ultrathin TiO 2 (B) nanosheets. The optimum photocatalytic H 2 evolution rate with 10 wt% Ni 2 P/TiO 2 (B) (3.966 mmol g−1 h−1) was superior to Pt loaded TiO 2 (B) (3.893 mmol h−1 g−1), which was 15 times higher than pure TiO 2 (B) nanosheets. Significantly, the new catalyst shows high stability and reusability in multiply cycled H 2 production runs for a 30 h period. The H 2 production rate can be considerably increased furthered by using synergistic photothermal H 2 evolution (20.129 mmol g−1 h−1 at 90 °C). [ABSTRACT FROM AUTHOR]

• The C-TA/g-C 3 N 4 was obtained by supramolecular self-assembly and thermal condensation. • The TA with groups OH can link with melamine promoting the condensation of g-C 3 N 4. • The C-TA/g-C 3 N 4 with decreased interlayer distance effectively promote charge transfer. • The condensed C-TA/g-C 3 N 4 exhibit superior photocatalytic H2 evolution performance. Design of highly condensed g-C 3 N 4 is a prospective way to optimize the photoreactivity of g-C 3 N 4 as it possesses condensed structure with decreased interlayer spacing, which benefits both charge transfer and light harvesting. Herein, we report that novel condensed carbonized-tannic acid (C-TA)/g-C 3 N 4 composites have been acquired via a supramolecular self-assembly of TA and melamine into TA/melamine precursors followed by thermal condensation. The acquired condensed C-TA/g-C 3 N 4 composites present superior visible-light photocatalytic activity for H 2 evolution. The 1 wt% C-TA/g-C 3 N 4 composite shows 4.2 times enhancement of photocatalytic activity for H 2 evolution compared to pristine g-C 3 N 4. The TA with distinct adhesion properties and functional groups of OH, which is firmly linked with melamine, can confine the melamine inside to promote the condensation to gain more condensed g-C 3 N 4. The condensed C-TA/g-C 3 N 4 composites with decreased interlayer distance effectively promote charge transfer and photocatalytic H 2 evolution. [ABSTRACT FROM AUTHOR]

A FAPbBr 3 /MoS 2 heterostructure was fabricated by in-situ growth of FAPbBr 3 on the MoS 2 surface for dehydrogenation of aromatic alcohols, which efficiently produces H 2 and aldehydes under visible light. [Display omitted] • FAPbBr 3 -wrapped MoS 2 was constructed for dehydrogenation of aromatic alcohols. • Notable visible-light-driven coproduction of H 2 and aldehydes is realized. • Experimental and thermotical studies reveal that type-II heterojunction is formed. • The enhanced photoactivity and reaction mechanism over the composite was disclosed. Photocatalytic H 2 evolution from organics dehydrogenation has sparked tremendous research attention. Metal halide perovskites (MHPs) with unique photoelectrical properties are deemed as a promising new-generation photocatalysts. Here, FAPbBr 3 -wrapped MoS 2 heterostructure photocatalysts are in-situ constructed by an anti-solvent method for photocatalytic dehydrogenation of aromatic alcohols, which realizes a co-production of clean H 2 fuel and value-added aldehydes. Experimental characterizations and theoretical calculations disclose that the introduction of MoS 2 decreases the size of the FAPbBr 3 , and forms a built-in electric field in the composite, which synergistically inhibit the electron-hole pairs recombination and enhance the charge separation. Meanwhile, the MoS 2 with low hydrogen binding energy provides abundant reduction sites to accelerate the kinetic of H 2 evolution. As a consequence, the optimal FAPbBr 3 /MoS 2 -7 composite exhibits a H 2 evolution rate of 1150 μmol g−1 h−1 and a benzyl aldehyde (BAD) generation rate of 1040 μmol g−1 h−1 under visible light irradiation, which is about 6 times of blank FAPbBr 3. The activity is comparable to the reported value of H 2 production from photocatalytic haloid acid splitting using MHPs-based catalysts. Electron paramagnetic resonance (EPR) measurement reveals that carbon-centered radical of •CH(OH)Ph is the primary intermediate for the photocatalytic dehydrogenation of aromatic alcohols. [ABSTRACT FROM AUTHOR]

[Display omitted] • W 2 C nanowires modified with Ni nanoparticles were fabricated as a HER catalyst. • The introduction of Ni nanoparticles can accelerate the water dissociation. • The electronic modulation between W 2 C and Ni can promote hydrogen desorption. • The W 2 C-Ni/CC exhibits excellent HER performance in alkaline electrolytes. Accelerated water dissociation and boosted hydrogen desorption ability are key challenges to improve the kinetics of alkaline hydrogen evolution reaction (HER). Herein, an electrocatalyst consisting of W 2 C nanowires modified by Ni nanoparticles grown on carbon cloth (W 2 C-Ni/CC) is presented. It requires low overpotentials of 37 and 227 mV to drive current densities of 10 and 100 mA cm-2 in 1.0 M KOH, respectively, which not only outperforms most of the W 2 C-based materials that have been reported, but also has catalytic activity comparable to that of commercial Pt/C. The experimental results show a strong synergistic effect between Ni nanoparticles and W 2 C nanowires, with reduced charge transfer resistance and accelerated electron transport in HER process. Further theoretical calculations indicate that the introduction of Ni nanoparticles can significantly accelerate the dissociation of adsorbed water while regulating the position of the W 2 C d-band center, thus weakening the hydrogen adsorption capacity. This work demonstrates that accelerating the dissociation of water and optimizing hydrogen adsorption by introducing metal Ni on the catalyst surface is an effective way to develop efficient catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • A composite electrocatalyst with CuCo alloy in nanoparticles and CoO in oxide phase in nanosheets was synthesized via a facile co-reduction method. • The CuCo-CoO composite electrocatalyst reached a maximum ammonia production rate of 12.63 mmol·h−1·cm−2 at −0.5 V vs RHE, and a FE up to 96.68% at −0.3 V vs RHE, and maintained over 40% of its initial ammonia yield rate for 48 h. • The DFT calculations revealed the origin of the improved catalytic performance from the enhanced capability for HER suppression on both CuCo and CoO. • It offers a possible way to enhance the NO3RR activity, selectivity, and selectivity by utilizing both metallic alloy and oxide. Electrochemical nitrate reduction reaction (NO3RR) to ammonia has attracted great attention for providing a novel and energy-conserving way to produce ammonia. However, it remains a challenge to develop an electrocatalyst that simultaneously has excellent activity, selectivity and stability. Herein, we present a CuCo-CoO composite electrocatalyst synthesized via a facile co-reduction method, achieving a maximum ammonia yield rate of 12.63 mmol·h−1·cm−2 at −0.5 V vs RHE and the highest faradic efficiency (FE) up to 96.68% at −0.3 V vs RHE. Meanwhile, the composite electrocatalyst maintains over 40% of its initial ammonia yield rate for 48 h, which is 3 times better than the reference Cu/C electrocatalyst. Physicochemical characterizations with density functional theory (DFT) calculations reveal that the stronger inhibition of hydrogen evolution reaction (HER) on the composite electrocatalyst can lead to the better ammonia yield rate and FE despite limited improvement in NO3RR activity. In addition, the introduction of bimetal alloy and especially cobalt oxide together contribute to the enhanced stability performance compared to monometallic Cu/C. [ABSTRACT FROM AUTHOR]

In order to improve the application of transition metal materials in catalyzing overall water splitting, a self-supporting Prussian blue analogues-based hierarchical architecture with abundant active sites (PBA@MnO 2) is established for OER catalysis. Meanwhile, the corresponding nitrided derivatives (N-FeMnNi) are easily obtained for efficient HER catalysis. [Display omitted] • Facile hydrothermal method was used to obtain PBA@MnO 2 hierarchical structure. • Low OER overpotential of 238 mV for PBA@MnO 2 -150/30 in 1.0 M KOH was obtained. • Low HER overpotential of 101 mV for N-FeMnNi-130/10 in 1.0 M KOH was gained. • High durability was shown during long-term electrochemical test. • The hierarchical PBA and derivative catalyst was applied to full water splitting. Assembling a hierarchical well-defined Prussian blue analogues (PBA) construction is a useful way to take earth-abundant elements into application toward hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Herein, we report a unique strategy for in-situ grafting three-dimensional (3D) MnFe-PBA cubes on the top of two-dimensional (2D) MnO 2 nanosheet arrays (PBA@MnO 2) via a facile two-step hydrothermal method with the participation of Ni foam (NF). After experiencing low-temperature pyrolysis in NH 3 /Ar atmosphere, the above catalysts are transformed into metal-nitride derivatives (N-FeMnNi). Remarkably, when operated in 1.0 M KOH aqueous solution, the as-obtained PBA@MnO 2 -150/30 (where 150 and 30 represent the hydrothermal temperature (°C) and the concentration of K 3 Fe(CN) 6 (mM) for preparation, respectively) shows the most outstanding OER activity, with an overpotential of 238 mV at 10 mA cm−2. Moreover, N-FeMnNi-130/10 requires an overpotential of 101 mV to reach 10 mA cm−2 for HER. As a result, the two samples are organized to establish a two-electrode cell, with a voltage of only 1.60 V needed to reach 10 mA cm−2. Meanwhile, it can stably work for 30 h without obvious current attenuation. This work provides a brand new perspective for the design of PBA electrocatalysts towards high-efficiency overall water splitting. [ABSTRACT FROM AUTHOR]

A hierarchical MoS 2 /MoO 2 nanostructure is presented as a highly efficient catalyst for the hydrogen evolution reaction (HER), which is prepared via a facile hydrothermal route in the absence of templates. The influence of various Mo sources has been studied and the roles of MoS 2 shell and MoO 2 core are discussed. It is found that the MoS 2 /MoO 2 nanostructures derived from the MoO 2 nanobelts exhibit the best HER activity, and the HER performance is strongly affected by the relative contents of MoS 2 shell and MoO 2 core, which correspond to the mass transport ability and the electron transfer ability, respectively. [ABSTRACT FROM AUTHOR]

In this work, electrocatalysts like the metal phosphides Ni 2 P, NiCoP, and FeP, can serve as cocatalysts of TiO 2 to form efficient composite photocatalysts for hydrogen generation from an aqueous methanol solution. On comparing Ni 2 P, NiCoP, and FeP and optimizing their proportions, the NiCoP(1 wt%)/TiO 2 composite was found to exhibit the highest activity toward photocatalytic H 2 production (1.54 μmol h −1 mg −1 ), which is about thirteen times that of the naked TiO 2 nanoparticles. Mott-Schottky (MS) analysis indicated that the large upward shift or band bending of the Fermi energy level ( E F ) in metal phosphides was responsible for the enhanced activity of the composites. The steady-state photoluminescence (PL) spectra and photocurrent transient response further confirmed that the enhanced photoinduced charge transfer and band separation after TiO 2 was integrated with the metal phosphides. Thus, these electrocatalysts were shown to be efficient cocatalysts that can replace noble metals as low-cost photocatalytic H 2 production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Co@WS 2 /Co@MoS 2 heterostructure with double-layer Co doping was designed and synthesized. • Interfacial doping engineering adjusts the surface electronic structure and further optimizes the catalytic performance. • The optimized d-band state and the formation of hybrid interface account for its good HER activity. • The Co@WS 2 /Co@MoS 2 exhibits excellent HER catalytic performance and stability in alkaline environment. Activating inert basal planes of transition metal composites through interfacial engineering and electronic modulation shows great potential on electrocatalytic hydrogen evolution reaction (HER). However, rational design of heterojunction structures through interfacial doping engineering still remains a costly and complicated challenge. Foreign atom doping can change the local electronic structure of the catalyst and adjust its catalytic performance. In this paper, the HER catalytic performance of WS 2 /MoS 2 heterostructure is strongly boosted for the first time by double-layer Co doping, which could not only induces the formation of Co@WS 2 /Co@MoS 2 hybrid interface but also regulates its d-band state. Additionally, activating the inert basal planes of the transition metal complex provides excellent electrocatalytic HER activity. Under the guidance of density functional theory (DFT) theory, a series of cobalt doped WS 2 /MoS 2 -based catalysts were systematically synthesized using a hydrothermal method. The prepared Co@WS 2 /Co@MoS 2 catalyst exhibited remarkable electrochemical activity and durability in alkaline environment, with an extra-low overpotential of 117 mV for HER to deliver a current density of 10 mA·cm−2. The experimental results clearly prove the prediction of DFT simulations. This work provides new insights of interface structure construction for high-performance hydrogen evolution catalysts by adjusting the electron distribution. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electrocatalyst RuMnO x could be activated through reconstruction when the chronoamperometric electrolysis potential below 1.10 V. • The reconstruction process was triggered by the dissolution and redeposition of Mn and Ru atoms. • Post-0.8 V RuMnO x with more than 30 % activity improvement @1.7 V after activation. • The activity was enhanced by more hydroxyl adsorption on the surface. • Post-0.8 V RuMnO x showed robust durability with a 70 mV increase for 2,600 h at current density of 10 mA cm−2. Transition metals-doped noble electrocatalysts are commonly applied for the acidic oxygen evolution reaction (OER). Notwithstanding, most transition metal oxides are unstable under the conditions of acidic OER, questioning the real active sites on the surface of the electrocatalyst. Herein, RuMnO x is explored more than 30 % activity increased (at 1.7 V) after chronoamperometric activation measurement. The activities are improved when the chronoamperometric measurement potentials below 1.1 V. Coupling electrochemical measurements with Mn dissolution and Ru redeposition studies, we verify that the reconstruction of catalysts is responsible for the activated electrochemical activities. Furthermore, we demonstrate that the activity is enhanced by more hydroxyl adsorption on the surface, and the activated RuMnO x shows robust durability with a 0.027 mV/h potential increase rate for 2,600 h at current density of 10 mA cm−2. [ABSTRACT FROM AUTHOR]

• Tridoped defect-rich porous carbon-based electrocatalyst was synthesized. • Electrocatalyst (GNP-900) featured with high surface area and enormous defect sites. • GNP-900 has excellent trifunctional catalytic performances of HER, OER, and ORR. Electrocatalytic hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) are practical mechanisms for sustainable energy conversion and storage. Metal-based electrocatalysts are widely used in the above fields. However, metal-based electrocatalysts have many disadvantages, including resource scarcity, low durability, and damaging environmental effects. To address this dilemma, we investigated a simple pyrolysis mode to synthesize a nitrogen (N), phosphorus (P), and oxygen (O) -doped (i.e., tridoped) defect-rich porous carbon-based electrocatalyst, named as GNP-900, for HER, OER, and ORR by heating the assembled hybrid super molecule of graphene oxide (GO), phytic acid (PA), and polyethyleneimine (PEI) at 900 °C. The developed GNP-900 shows high electrocatalytic activities for HER and OER with low Tafel slopes of 93 mV dec−1 and 127 mV dec−1 and small overpotentials of 179 mV and 299 mV, respectively, to achieve the current density of (j) ± 10 mA cm−2. For ORR, the GNP-900 offers a very small loop current density and presents good CH 3 OH tolerance. In addition, features with a positive onset potential of 0.96 V and half-wave potential (E 1/2) of 0.824 V, strongly suggesting the high electrocatalytic performance. The excellent electrocatalytic performance of the porous GNP-900 is mainly ascribed to the tridoped heteroatoms and the abundant defect sites on the substrate. [ABSTRACT FROM AUTHOR]

A fascinatinal amorphous NiFe layered double hydroxides nanosheets modified with boron nanoclusters was fabricated to provide a unique crystalline-amorphous interface and highly active reactive sites. It has remarkable bifunctional electrocatalytic properties for both AOR and HER under alkaline conditions. [Display omitted] • An amorphous NiFe layered double hydroxides nanosheets modified with boron nanoclusters (B-NiFe-LDH/NF) was successfully constructed by a facile hydrothermal coupled with electroreduction method. • The B-NiFe-LDH/NF exhibited remarkable electrocatalytic capacity toward AOR and HER by the introduction of boron nanoclusters. • Density functional theory (DFT)calculations confirm boron nanoclusters can effectively tune the electronic structure to lower the energy barrier in AOR and HER process. Coupling ammonia oxidation reaction (AOR) and hydrogen evolution reaction (HER) provides a hybrid water splitting system to reduce the energy consumption of hydrogen production significantly, solve the safety problem of H 2 /O 2 mixing in the overall water splitting, and remove ammonia nitrogen from wastewater. Herein, amorphous boron nanoclusters are deposited onto NiFe layered double hydroxide nanosheets (B-NiFe-LDH/NF) via in-situ electroreduction, proposed to form a bifunctional catalyst toward the AOR and HER. Since the electron-deficient boron induces surface electronic recombination of LDH and facilitates the exposure of substantial high-valent Ni and Fe metal active sites, this B-NiFe-LDH/NF exhibited high activity with a voltage of 1.781 V at a current density of 100 mA cm-2, 202 mV lower than that required in overall splitting water, accompanying with 78.6% of the ammonia removal rate after 24 h of electrolysis. In addition, density functional theory (DFT) simulation indicated that the induction of boron nanoclusters decreased the energy barrier, facilitating the adsorption–desorption of ammonia and the Volmer step. [ABSTRACT FROM AUTHOR]

A new class of surface coating materials of lithium titanium orthophosphate [LiTi 2 (PO 4) 3 , LTP] was introduced to modify the CdS photocatalyst. The LTP shell on the surface of the CdS core can effectively transfer the interfacial photogenerated electrons to produce hydrogen. Furthermore, this shell prevents reverse reaction between H 2 and O 2 during photocatalytic overall water splitting. [Display omitted] • LiTi 2 (PO 4) 3 was first used as a surface coating material to modify photocatalysts. • A one-dimensional CdS@LiTi 2 (PO 4) 3 core–shell photocatalyst was prepared via a simple sol–gel method. • LiTi 2 (PO 4) 3 shell can effectively transfer the interfacial photogenerated electrons to produce hydrogen, as well as prevent a reverse reaction between H 2 and O 2. • CdS@LiTi 2 (PO 4) 3 showed improved photocatalytic activity and photochemical stability than those of CdS. Two major challenges in photocatalysis are the separation and utilization of photogenerated charge carriers that have limited their wider applications. To address these issues, significant studies have been devoted to the surface modification of photocatalysts. Herein, CdS nanorods were surface-modified by an ion-conducting LiTi 2 (PO 4) 3 (LTP) shell. This modification could accelerate the rapid separation and efficient utilization of photoinduced charge carriers. Therefore, CdS@LTP composite photocatalyst displayed a photocatalytic H 2 evolution rate of 26.01 mmol g−1h−1 without any addition of cocatalysts in a Na 2 S/Na 2 SO 3 solution, which was over 6-fold compared to CdS, and showed improved stability. Furthermore, this shell can prevent the reverse reactions between H 2 and O 2 during photocatalytic water splitting. With the photo-deposition of Pt cocatalysts, CdS@LTP-Pt can achieve efficient overall water splitting with the highest H 2 generation rate (351 μmol g−1h−1), which is 3.25 times higher than that of CdS-Pt. This study broadens the application of ionic conductor materials and provides a new way for the design of advanced photocatalysts for solar energy conversion. [ABSTRACT FROM AUTHOR]

Nickel-iron phosphides hollow nanospheres as pre-catalysts for electrochemical water oxidation in alkaline solution were synthesized through a low-temperature solvothermal method using metal-organic framework precursors. • Low-temperature solvothermal phosphorization to synthesize nickel-iron phosphides. • (Ni 0.73 Fe 0.27) 2 P as precatalysts exhibit excellent water oxidation activities. • Transformation of phosphides to layered double hydroxides was observed. • Demonstration of solar-to-hydrogen device was constructed. Developing active and stable water oxidation electrocatalysts is desired to increase the efficiency of water electrolyzers. Nickel phosphides have been reported as pre-catalysts for water oxidation reaction. However, their catalytic activities can further be improved through morphology engineering and tuning electronic structures. Here, nickel-iron phosphides hollow nanospheres ((Ni 1-x Fe x) 2 P, x = 0–0.35) were synthesized through solvothermal treatment of Ni-Fe metal-organic framework precursors with white phosphorus. The hollow nanospheres have diameters around 20–50 nm, with the crystalized structure resembles Ni 2 P phase. When used to catalyze the water oxidation reaction in 1 M KOH, the (Ni 0.73 Fe 0.27) 2 P/Ni foam electrode exhibits best catalytic performance, with only 243 mV overpotentials to reach 10 mA cm−2 (loading 0.135 mg Ni+Fe cm−2), and with a Tafel slope ~ 30 mV dec−1. The enhanced water oxidation activity is mainly owing to the electronic interaction between Ni and Fe. Ex-situ characterizations of the (Ni 0.73 Fe 0.27) 2 P after water oxidation reaction reveal that surface phosphides are transformed into layered double hydroxides under anodic alkaline conditions. The solvothermal prepared (Ni 1-x Fe x) 2 P hollow nanospheres can be a potential candidate as pre-catalysts for water oxidation reaction in water electrolyzers. [ABSTRACT FROM AUTHOR]

• The Co NPs@CNT is produced by one-step chemical vapor deposition at 600 °C. • The Co NPs@CNT possesses superior catalytic activity and durability for OER. • Porous hollow structure can facilitate the charge transfer and mass transport. • The synergetic interaction optimizes the adsorption energy of OH*, O* and OOH*. Low-cost, environmentally friendly, and efficient electrocatalysts are required for large-scale and commercial generation of O 2 and H 2 by the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, composites composed of Co and carbon nanotubes (Co NPs@CNT) are fabricated by one-step chemical vapor deposition (CVD) using commercial Co nanoparticles and benzene as precursors. In the alkaline medium, Co NPs@CNT exhibits a small overpotential of 380 mV at a current density of 10 mA cm−2, small Tafel slope of 82.2 mV dec−1, and excellent structural and electrochemical durability and the properties are better than those of most previously reported Co-based electrocatalysts and commercial Co nanoparticles. The CNTs not only provide high conductivity, but also decrease the adsorption energy of OH* on the surface of Co NPs@CNT. The small energy barrier is responsible for the enhanced OER performance of Co NPs@CNT. In addition to the revelation of the synergistic effects between Co and CNTs, our results provide insights into the development of metal-carbon electrocatalysts and the simple and effective strategy described here has large commercial potential. [ABSTRACT FROM AUTHOR]

Conformal deposition and effective use of catalysts based on 3D electrode architectures are of great importance in electrocatalytic applications. In this work, 3D porous Ni substrate is first fabricated through a hydrogen bubbles dynamic templated method, and well-dispersed Pt nanoparticles are loaded on the substrate subsequently via atomic layer deposition. The 3D porous Ni/Pt is utilized as an efficient hydrogen evolution reaction catalyst. The 3D and high surface area structure is realized through the hydrogen bubbles dynamic templated method. The synergistic effect between atomic-layer-deposited Pt and the 3D structure of porous Ni substrate finds a new approach of minimal yet effective utilization of Pt for much enhanced HER activity. The 3D porous Ni/Pt samples show comparable activity performance with commercial 20 wt% Pt/C. Furthermore, according to the Pt mass-based calculation, only ~0.1 wt% Pt was deposited on 3D porous Ni substrate electrocatalysts which exhibits a much higher activity than the commercial 20 wt% Pt/C catalyst. Unlabelled Image • 3D porous nickel substrate is fabricated though a reported method. • Pt nanoparticles are deposited on the substrate via atomic layer deposition. • The Pt nanoparticles are well-dispersed on the substrate. • The Pt/3D porous nickel electrodes exhibit excellent activity for H 2 evolution. [ABSTRACT FROM AUTHOR]

Abstract Developing highly efficient non-noble-metal catalysts for the upgrade of abundant and low-cost renewable raw biomass into high-quality biofuels and important chemicals is especially desirable, but still remains huge challenges. Herein, Sn4+-induced highly dispersed Cu-based catalyst, Cu/Zn-Al-Sn layered double hydroxide (Cu/ZnAlSn-LDH), is delicately constructed for catalytic transfer hydrodeoxygenation of vanillin to promising 2-methoxy-4-methylphenol (MMP) biofuel using 2-propanol as hydrogen source and solvent without any external hydrogen supply. Nearly total MMP yield is achieved under moderate reaction conditions (180 °C, 4 h) and the turnover number (TON) value calculated in Cu/ZnAlSn-LDH is about 3 times higher than that in Sn-free catalyst (Cu/ZnAl-LDH). Characterizations results reveal that the Sn4+ species confined in the lattice of brucite-like layer of ZnAlSn-LDH are existed in electron-rich state, which can promote the formation of smaller Cu nanoparticles (1.95 nm) in Cu/ZnAlSn-LDH compared to those in Sn-free Cu/ZnAl-LDH catalyst (6.08 nm), as well as stronger metal-support interaction, thus leading to the higher catalytic performance and stability. The present findings offer a new avenue to strategically fabricate highly dispersed non-noble metal catalysts with enhanced catalytic performance by adjusting surface structures and compositions of supports for a wide range of hydrodeoxygenation of other biomass-derived compounds without any external hydrogen. Highlights • Highly dispersed Cu-based catalyst was skillfully fabricated by the inducement of Sn4+ species confined in the layer of LDH. • Strong interactions between Cu species and ZnAlSn-LDH support were formed. • Excellent catalytic transfer hydrodeoxygenation performance was achieved under atmospheric N 2. • Cooperative effect among three key factors (i.e. surface basic sites, highly dispersed Cu0 NPs and Cu+ species) was confirmed. [ABSTRACT FROM AUTHOR]

We present a strategy for single-atom induced catalytic site transfer. The catalyst Co/C-BN with new active sites exhibits excellent photocatalytic activity and selectivity of CO in pure water. [Display omitted] • Cobalt single atom induces catalytic active site shift from CN 3 to CB 3. • The introduced Co atom changes the spin density of the neighboring catalytic site. • Co/C-BN exhibits excellent photocatalytic activity without sacrificial reagents. • The possible photocatalytic reaction mechanisms are revealed in depth. Active site tuning in catalyst design is the key to improving the catalyst performance. Herein, we introduce single cobalt atoms into carbon-doped boron nitride (C-BN) and find, to our surprise, that the photocatalytic CO 2 reduction site of C-BN shifts from CN 3 to CB 3. The catalyst Co/C-BN with new active sites exhibits excellent photocatalytic activity and selectivity of CO without adding sacrificial reagents, while the side reaction of hydrogen evolution is significantly inhibited. Theoretical calculations show that the introduced Co atom changes the spin density of the neighboring catalytic site, thus regulating the adsorption energy of the catalytic site for active intermediates (COOH*). Compared with CN 3 site, CB 3 in Co/C-BN shows superiority in CO* formation elementary step for the conversion of CO 2 to CO, and inhibits the generation of adsorbed H 2 in the competitive water-splitting reaction. This work provides valuable insights into the design of highly efficient catalysts in the future. [ABSTRACT FROM AUTHOR]

[Display omitted] • Composition of Mo-based nanoparticles embedded in carbon matrix is delicately controlled by initiator amount/calcination temperature. • N, S-doping and rich oxygen vacancies provide numerous catalytic defects. • Mo 2 C-Mo/C heterogeneous nanorods with abundant active heterointerfaces display remarkable HER activity and long-term durability. Interfacial engineering of cost-effective non-noble materials is attractive for synthesizing advanced electrocatalysts toward hydrogen evolution reaction (HER). Herein, we prepare N, S-doped Mo 2 C-Mo/C heterogeneous nanorods (NSMB-1.25) with abundant active heterointerfaces and defect sites via in situ polymerization and carburization strategy. The polyaniline-derived heteroatom-doped carbon acts not only as a matrix but also as a carbon source for Mo 2 C formation. The phase transition of Mo 2 C-Mo heterostructure is accurately regulated by delicately varying the dosage of the polymerization initiator and calcine temperature. The synergistic effects of Mo 2 C, metallic Mo and N, S doping carbon significantly enhance the HER activity and durability of nanorods. Benefiting from the plentiful active sites of the Mo 2 C-Mo heterointerfaces, fast charge and mass transfer channels, heteroatomic doping and large surface area, the as-prepared NSMB-1.25 nanorods deliver only 118 mV overpotential at 10 mA cm−2 current density, small Tafel slopes of 74 mV dec-1, high exchange current density of 25.84 × 10-2 mA cm−2 and excellent stability in 1.0 M KOH solution. This work may support a feasible strategy for reasonably designing highly active heterogeneous interfaces to achieve efficient energy conversion and storage. [ABSTRACT FROM AUTHOR]

[Display omitted] • Amorphous NiCoP dendrites were homogenously in-situ grown on nickel foam (NiCoP@NF) through a smart electroless plating strategy. • The NiCoP@NF could afford a j of 10 mA cm−2 at a low η of 0.263 V. • A greatly decreased charge transfer resistance of 1.53 Ω cm2 at 1.553 V was achieved. • This material shows a better stability, a higher MA and a larger TOF than its pristine counterpart. • The underlying mechanism credited for the enhanced OER performance are explored. Developing cost-effective and precious-metal-free nanomaterials capable of efficiently driving oxygen evolution reaction (OER) is pivotal in the ultimate pursuit of desirable electrochemical devices. Herein, amorphous NiCoP dendrites were homogenously in-situ constructed on nickel foam (NiCoP@NF) through a smart electroless plating strategy. The NiCoP@NF is highly active and stable toward OER, where a greatly decreased charge transfer resistance of 1.53 Ω cm2 at 1.553 V, a comparably lowered overpotential (η) of 263 mV and a good long-term stability of 12 h with negligible degradation at a current density (j) of 10 mA cm−2 are achieved relative to its counterpart, together with a remarkably enhanced turnover frequency (TOF) of 1.74 s−1 and a considerably increased mass activity (MA) of 154.5 A g−1 at a η of 0.27 V. The exceptional performance originates from the unique architecture of NiCoP@NF and synergistic interplay of Ni and Co with an appropriate atomic ratio, where the dendrites not only ensure substantial exposed active sites, but also guarantee fast mass transport and reduced contact resistance, while the synergy moderately tunes the electronic structure to lower the activation energy for reaction kinetics with optimal adsorption and desorption processes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electronic properties of ZnSe monolayer and its graphene-based heterostructures are systematically studied. • The external electric field can significantly modulate the charge distribution. • The external electric field can effectively tune the SBH value and contact type. • We proved that ZnSe owns high catalytic acivity of OER/HER/ORR performance. The graphene-based Van der Waals (vdW) heterostructures show great potential for the next generation of photoelectronic nanodevices. Here, we constructed the ZnSe/graphene vdW heterojunction and investigated its structural, electronic, optical, transportable, and catalytic properties by using density functional theory (DFT). The results show that ZnSe is a direct semiconductor with a bandgap of 3.24 eV. The electron mobility of ZnSe is seven times higher than that of the hole, which is beneficial for the photogenerated hole-electron separation. Besides, the n-type Schottky to Ohmic contact transformation can be realized by applying an external electric field of 0.2 V/Å, and the underlying mechanism is discussed. Finally, the potential ability of photo/electrocatalysis for graphene/ZnSe heterostructure and electrocatalysis for ZnSe monolayer is also explored. The hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) can spontaneously activate in acid (PH = 1,2) and alkaline (PH > 9) media under light irradiation. The overpotential of oxygen reduction reaction reaches 0.42 eV, which indicates graphene/ZnSe heterostructure would be a potential electrocatalyst. For the HER process of ZnSe monolayer, the overpotential is significantly decreased to 0.23 eV by doping 3d transition metal atom. Consequently, we hope our work can provide useful guidance for designing practical ZnSe-based applications. [ABSTRACT FROM AUTHOR]

By skillfully introducing a conjugate electron donating ring into the g-C 3 N 4 framework, the as-prepared 3 wt% PPD/CN sample not only narrows the bandgap of g-C 3 N 4 , but also absorbs more solar light up to 600 nm. As a result, the optimal sample exhibited hydrogen escape under orange light (600 nm) and bare g-C 3 N 4 had almost no such performance. [Display omitted] • Benzene ring doping in the specific site of the network of g-C 3 N 4 was obtained. • It still has photoactivity that g-C 3 N 4 barely has under the orange light. • The 3 wt% PPD/CN can effectively cover more sufficient photo flux (λ = 600 nm). • The benzene ring incorporation of g-C 3 N 4 enhanced photogenerated carrier separating. Grafting π-conjugated donor units into graphitic carbon nitride (g-C 3 N 4) represents a promising alterative to improve its light absorption range and charge transfer kinetics. To this end, we here report an efficient intramolecular g-C 3 N 4 -based conjugated copolymers via the one-spot thermal copolymerization for not only reduces the bandgap to 2.56 eV and thus expand the visible-light harvesting capability, but also accelerates the separation ability of photogenerated excitons. Consequently, the copolymer of 3 wt% p-phenylenediamine with melamine exhibits extraordinary hydrogen (H 2) evolution rate of 1040 μmol g−1 h−1 under visible light. Interestingly, it still shows hydrogen production (5.29 μmol g−1 h−1) at λ = 600 nm (orange light). Systematic characterizations have proved that the optimal sample has high photocatalytic activity, due to rapid charge transfer kinetics and exciton separation. Our work sheds light on a molecular design to regulate charge-transfer dynamics among of polymeric semiconductors towards efficient solar-to-H 2 production. [ABSTRACT FROM AUTHOR]

[Display omitted] • Metallic MoS 2 and amorphous CoNi(OH) 2 show a synergistic effect for HER in 0.1 M KOH. • MoS 2 -CoNi(OH) 2 composite has higher current response for HER than Pt/C at η greater than 0.19 V. • MoS 2 -CoNi(OH) 2 composite also shows highly efficient OER performance in 0.1 M KOH. We report the preparation of nanocomposite consisting of metallic MoS 2 and electrodeposited amorphous CoNi(OH) 2 nanosheets on carbon paper for efficient electrochemical water splitting in the alkaline solutions. The synergistic effect between metallic MoS 2 and amorphous CoNi(OH) 2 nanosheets enables the excellent catalytic activity of nanocompsite towards hydrogen evolution reaction (HER) in 0.1 M KOH with a low overpotential of 178 mV at a current density of 10 mA/cm2 and Tafel slope of 60.9 mV/decade. The current density of MoS 2 -CoNi(OH) 2 nanocomposite for HER at the overpotential of more than 0.190 V is even higher than that of the commercial Pt/C catalyst. Moreover, the MoS 2 -CoNi(OH) 2 nanocomposite is also active towards electrochemical oxygen evolution and can act as a bifunctional catalyst for water splitting in 0.1 M KOH. Our work povides a simple and effective way to engineer phases and prepare two-dimensional nanocomposites for effecient water splitting in alkaline aqueous solutions. [ABSTRACT FROM AUTHOR]

Herein, In-situ conversional mycelium-like metal phosphides-encapsulated N, P co-doped carbon nanotubes coating on the stainless steel mesh (PSD-SM) as self-supporting electrocatalyst was fabricated via solid-diffusion and phosphorization process, which was the first time to fabricated the "chainmail for catalysts" use stainless steel mesh worked as self-reaction template and electrode-base materilas. The in-situ transformational mycelium-like CNTs array structure greatly enhanced the specific surface area of steel mesh and the graphitized carbon layer coating with high capacitance increases the electrochemical active sites. And the subsequent phosphorization treatment further improved the intrinsic catalytic activity of the material. The PSD-SM exhibits the low overpotential of 231 mV at 10 mA·cm−2 with a Tafel slope of 88 mV·dec−1 for OER and 172 mV at 10 mA·cm−2 with a Tafel slope of 125 mV·dec−1 for HER. [Display omitted] • In-situ conversional mycelium-like metal phosphides-encapsulated N, P co-doped CNTs coating on the stainless steel mesh (PSD-SM). • Implemented the necessary physical and chemical characterization to test PSD-SM. • PSD-SM show excellent catalytic performance, and its electrocatalytic mechanism is investigated in detail. • The synergistic effect of multiple catalytic active centers results in superior catalytic performance. Herein, In-situ conversional mycelium-like metal phosphides-encapsulated N, P co-doped carbon nanotubes (CNTs) coating on the stainless steel mesh (PSD-SM) as self-supporting electrocatalyst was fabricated via solid-diffusion (SD) and phosphorization process, which was the first time to fabricated the "chainmail for catalysts" use stainless steel mesh worked as self-reaction template and electrode-base materilas. The in-situ transformational mycelium-like CNTs array structure greatly enhanced the specific surface area of steel mesh and the graphitized carbon layer coating with high capacitance increases the electrochemical active sites. And the subsequent phosphorization treatment further improved the intrinsic catalytic activity of the material. PSD-SM exhibits the low overpotential of 231 mV at 10 mA·cm−2 with a Tafel slope of 88 mV·dec−1 for OER and 172 mV at 10 mA·cm−2 with a Tafel slope of 125 mV·dec−1 for HER. Further more, there are only 1.77 V deliver potential for water electrolysis of PSD-SM at 10 mA·cm−2 and the kinetic mechanism of as-fabricated samples for HER and OER was analyzed by Tafel slope and other measurement. This report provides an promising method to prepare efficient and robust electrocatalytic materials based on steel mesh for practical application. [ABSTRACT FROM AUTHOR]

The Bi 2 MoO 6 (BMO) nanosheet array on nickel foam was synthesized via hydrothermal method. Subsequently, the NH 3 plasma modification was utilized to enable synchronous N doping and O vacancies on the surface of BMO (N-BMO). The nanosheet structure and numerous O defects could provide sufficient active sites for adsorbed ions (especially in alkaline electrolyte). Used for supercapacitors, such N-BMO electrode achieved more than twice capacitance than pristine BMO. Compared with BMO, the N-BMO further revealed enhanced catalytic activity during oxygen evolution reaction process. • Bi 2 MoO 6 nanosheet array was synthesized through one-step hydrothermal method. • O defects and N doping (N-BMO) were achieved through NH 3 plasma modification. • The N-BMO electrode delivered high capacitance retention (79.0% of capacitance retention after 10,000 cycles at 20 Ag−1). • The N-BMO exhibited good catalytic activity with small Tafel slope of 42 mV dec–1. Benefiting from tailorable component and structure, metal oxides exhibit great impetus towards high performance supercapacitors and oxygen evolution reaction catalyst. However, rational structural regulation of metal oxides-based electrode under mild conditions to simultaneously achieve abundant active sites and synergistic effects of multiple active centers is still very challenging. In this study, the Bi 2 MoO 6 nanosheets with adequate oxygen vacancies and heteroatom nitrogen injection were synthesized via hydrothermal reaction and subsequent NH 3 /Ar plasma modification. Controllable generation of O vacancies and injection of N atoms in Bi 2 MoO 6 was conducive to regulating the band structure of electrode material, achieving greatly enhanced conductivity, wettability, ionic infiltration capacity and significantly reduced dissociation barrier of surface adsorbates. Compared with pristine Bi 2 MoO 6 , the plasma engraved Bi 2 MoO 6 electrode delivered superior charge storage performance for supercapacitor (79.0% of capacitance retention after 10,000 cycles at 20 Ag−1) and good electrochemical catalytic efficiency for oxygen evolution reaction (349 mV at 10 mA cm−2 with a Tafel slope of 42 mV dec–1). It is demonstrated that the plasma modification for metal oxides is a promising application in supercapacitors and electrochemical water splitting. [ABSTRACT FROM AUTHOR]

[Display omitted] • hBN/g-C 3 N 4 with six different defected types are constructed and studied in detail. • Z-scheme vdW heterojunctions can realize stronger redox capacity. • A suitable band gap width can even obtain full visible light response. • Defect-engineered can increase even more than 20 times the charge transfer between layers. 2D/2D hBN/g-C 3 N 4 nanocomposites with good photocatalytic activity have been successfully prepared, and fortunately defected 2D material heterojunction opens up new possibilities for high-efficiency photocatalysts. However, its photocatalytic performance and mechanism in splitting water have not been thoroughly explored. Herein, using the state-of-theart TDHF-HSE06 method, 2D/2D hBN/g-C 3 N 4 nanocomposites with different defected types were discussed in detail, including C atoms doping and natural point vacancies. We demonstrate that the defect-induced Z-scheme vdW heterojunction is a key for excellent photocatalytic performance. Compared to perfect hBN/g-C 3 N 4 , the defected hBN/g-C 3 N 4 heterojunctions have stronger interfacial interaction with more than 20 times of charge transfer. And it even has full visible-light response due to the suitable band gap width. More importantly, the Z-scheme band edge potentials have perfect redox capacity for water splitting at both PH = 0 and 7. The findings not only explain the existing experimental phenomena, but also provide new insights into the design of high-efficiency metal-free photocatalysts. [ABSTRACT FROM AUTHOR]

The Mo and S co-doped porous g-C 3 N 4 nanosheets were successfully synthesized through a simple one-step heating technology. The doping of S and Mo widens the optical response range of g-C 3 N 4. The External Quantum Efficiency of 25 mg catalyst can still reach 0.09% at 500 nm with the absence of cocatalyst. • The porous structure of g-C 3 N 4 provides more active sites for efficient photocatalytic hydrogen evolution. • The doping of S and Mo widens the optical response range of g-C 3 N 4. • Good External Quantum Efficiency can be maintained even at λ = 500 nm. • Unique doping method can effectively shorten the electron transport path. • The preparation technology is simple and easy to realize. Herein, the doping effect of Mo and S on photocatalytic H 2 generation activity of g-C 3 N 4 under visible light irradiation is investigated. By using a simple one-step heating technology, Mo and S co-doped porous g-C 3 N 4 nanosheets were successfully prepared. The sublimation of sulfur powders promotes the formation of porous g-C 3 N 4 nanosheets with large specific surface area. The Mo and S co-doped g-C 3 N 4 exhibits efficient visible-light water splitting hydrogen evolution with the noble metallic cocatalyst free. The optimized Mo/S/g-C 3 N 4 -10 photocatalyst exhibits an extraordinary photocatalytic H 2 evolution rate of 294 μmol g-1h−1 under visible light irradiation (λ > 420 nm). The co-doping of S and Mo extends the optical response range of g-C 3 N 4. The doping process and electron transport path are analyzed in details. Mo and S co-doped porous g-C 3 N 4 catalysts also exhibit outstanding cycling stability. This work may inspire the facile synthesis of photocatalyst for efficient visible-light water splitting hydrogen evolution. [ABSTRACT FROM AUTHOR]

• MgAl-LDH nanosheets decorated with NiS ultrafine cocatalyst were obtained. • The photocatalytic hydrogen generation rate is substantially improved after the introduction of NiS. • NiS enhances the visible-light absorption and promotes the separation and transfer of photogenerated charges. • The photocatalyst is made up of low-cost and eco-friendly elements. Nonprecious cocatalyst decoration is of great importance to create more active sites on the photocatalyst surface and provides insights into the photocatalytic activity enhancement. Herein, through facile hydrothermal and precipitation routes, the surface of MgAl layered double hydroxide (LDH) was modified by ultrafine NiS nanoparticles as a cocatalyst to design MgAl-LDH/NiS hybrid photocatalysts for highly-efficient photocatalytic hydrogen generation. The presence of NiS not only enhances the visible-light absorption but also promotes the separation and transfer of photogenerated charges, thereby boosting the photocatalytic activity of MgAl-LDH/NiS (35.8 μmol h−1) compared with bare MgAl-LDH (2.7 μmol h−1). The MgAl-LDH/NiS hybrid, moreover, displays a superior stability towards photocatalytic hydrogen evolution. This research offers a facile route to develop a high-performance photocatalyst using low-cost metal sulfide as cocatalyst for visible light photocatalytic hydrogen production. [ABSTRACT FROM AUTHOR]