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The atomically controlled transition of nanohybrids and their effects on charge-carrier dynamics are highly desirable for fundamental studies in photocatalysis. Herein, for the first time, a method combining atomic monodispersity and single-atom alloy was used to prepare a new form of highly efficient silver-based cocatalysts (Ag25 & Pt1Ag24) on graphitic carbon nitride, representing a novel photocatalytic system for hydrogen evolution. [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-C 3 N 4 ) has aroused intense expectations owing to its outstanding visible-light-response capability for hydrogen generation from water. However, the low-yield, low practical surface area and high photogenerated charge recombination rate severely limits its photocatalytic performance . Here, in this study high-yield synthesis of g-C 3 N 4 with a large surface area has been achieved successfully through an in situ pyrolysis of cyanamide with the assist of the bifunctional urea. During the synthesis process, urea may decompose into a lot of ammonia and carbon dioxide, which acts as the supplementary-nitrogen-source and bubble-generating template respectively. It is found that the surface area and photocatalytic activity can be controlled by adjusting the addition of the environmentally friendly bifunctional urea. The as-prepared g-C 3 N 4 exhibits unique optical activity as well as photoelectriochemical activity for solar-to-chemical conversion, and this simple bifunctional method may open a new pathway for designing and optimizing of photocatalysts. [ABSTRACT FROM AUTHOR]

Facilitating charge-carrier separation and transfer is fundamentally important to improve the photocatalytic performance of semiconductor materials. Herein, two-dimensional hexagonal WO3 nanoplates were synthesized by a two-step route: rapid evaporation and solid-phase sintering. The as-prepared WO3 exhibits an enhanced activity of photocatalytic water oxidation compared to bulk monoclinic WO3. The electron dynamics analysis reveals that a more efficient charge-carrier separation in the former can be obtained, the origin of which can be attributed to an increased number of surface defects in hexagonal WO3 nanoplates. This work not only presents a novel and simple method to produce two-dimensional hexagonal WO3 nanoplates, but also demonstrates that surface defects and two-dimensional geometric structures can promote the charge separation, which may be extended to the design of other efficient photocatalysts. [ABSTRACT FROM AUTHOR]

Metallic nickel nanoparticles well dispersed in graphitized carbon matrix (Ni@C) by pyrolysis of metal-organic frameworks and leaching treatment of hydrochloric acid could greatly enhance the photocatalytic activity of g-C 3 N 4 under visible light irradiation. For 2.0 wt% Ni@C/g-C 3 N 4 , the average hydrogen evolution rate is 2.15 mmol h −1 g −1 , which is around 88 times higher than that of pure g-C 3 N 4 , and even better than that of platinum-loaded g-C 3 N 4 . The remarkably improved photocatalytic activities through loading Ni@C can be attributed to the cooperative work of Ni nanoparticles and graphene layers, which facilitate the separation of photo-generated carriers and suppress the recombination of the electron-hole pairs. In addition, the hollow onion-like structure can restrain the formation of Ni-hydrogen bonds which modulates desorption of hydrogen. Our studies may open up a promising strategy to design economical noble-metal-free co-catalysts for efficient solar energy conversion. [ABSTRACT FROM AUTHOR]

Porous oxygen-doped graphitic carbon nitride (g-C3N4) with feeble nitrogen vacancies was fabricated through thermal polycondensation of melamine with an appropriate amount of polyvinylpyrrolidone. After optimization, the bandgap of g-C3N4 can be narrowed by 0.2 eV and the specific surface area expanded, which contribute to increasing the utilization of solar energy. Consequently, the optimized g-C3N4 exhibits impressive enhancement in photocatalytic hydrogen evolution performance, by nearly 5 times compared with the pristine one under the irradiation of visible light. [ABSTRACT FROM AUTHOR]

The optimal ratio of reaction solutions resulted in excellent performance and product selectivity of CuO/g-C3N4 composites in the photocatalytic CO2 reduction reaction. A pH-dependent chemical exchange saturation transfer (CEST) imaging nuclear magnetic resonance (NMR) method was used to confirm that CuO modification improves the adsorption capacity of CO2. [ABSTRACT FROM AUTHOR]

Amino acids are the building blocks of proteins and are widely used as important ingredients for other nitrogen‐containing molecules. Here, we report the sustainable production of amino acids from biomass‐derived hydroxy acids with high activity under visible‐light irradiation and mild conditions, using atomic ruthenium‐promoted cadmium sulfide (Ru1/CdS). On a metal basis, the optimized Ru1/CdS exhibits a maximal alanine formation rate of 26.0 molAla ⋅ gRu−1 ⋅ h−1, which is 1.7 times and more than two orders of magnitude higher than that of its nanoparticle counterpart and the conventional thermocatalytic process, respectively. Integrated spectroscopic analysis and density functional theory calculations attribute the high performance of Ru1/CdS to the facilitated charge separation and O−H bond dissociation of the α‐hydroxy group, here of lactic acid. The operando nuclear magnetic resonance further infers a unique "double activation" mechanism of both the CH−OH and CH3−CH−OH structures in lactic acid, which significantly accelerates its photocatalytic amination toward alanine. [ABSTRACT FROM AUTHOR]

Engineering surface-active facets of metal cocatalysts is one of the most widely explored strategies to develop advanced photocatalysts and promote photocatalytic solar energy conversion. Here, the surface-active facets of Pd nanocrystals in Pd/g-C 3 N 4 photocatalyst was related to the injection flow rate of PdCl 2. When PdCl 2 was injected at a low flow rate of 7.5 mL/h (7.5-Pd/g-C 3 N 4), the Pd nanocrystals were uniformly dispersed onto the g-C 3 N 4 with exposed low-index {100} and {111} surface-active facets. However, increasing the injection flow rate to 150 mL/h (150-Pd/g-C 3 N 4) formed Pd nanocrystals where only the {100} surface-active facet was exposed. Under visible light irradiation, the 7.5-Pd/g-C 3 N 4 nanocomposite exhibited excellent water splitting activity for hydrogen production (7.61 mmol g−1 h−1), which was significantly better than with the 150-Pd/g-C 3 N 4 nanocomposite (3.3 mmol g−1 h−1). Theoretical calculations and experimental results confirm the importance of the {111} surface-active facets in the 7.5-Pd/g-C 3 N 4 nanocomposite for promoting photocatalytic activity. [Display omitted] • The Pd/g-C 3 N 4 photocatalyst was prepared in a simple one-pot synthesis method. • The surface-active facets of Pd nanocrystals in Pd/g-C 3 N 4 was controlled by the injection flow rate of PdCl 2. • 7.5-Pd/g-C 3 N 4 nanocomposite exhibited excellent photocatalytic activity for H 2 production. • 7.5-Pd/g-C 3 N 4 nanocomposite also shown good performance in varied photocatalytic reactions. [ABSTRACT FROM AUTHOR]

The construction of efficient and stable non-noble metal bifunctional electrocatalysts for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) presents a challenge in electrocatalytic water splitting. CoS 2 is a promising electrocatalyst that could replace precious metals. In this work, a series of Co-MOF precursors having average particle sizes ranging from the nanometer to the micron scale (86–1084 nm) were synthesized in an unprecedented attempt; Co/CoS 2 heterojunction embedded in nitrogen doped carbon framework (Co/CoS 2 @NC) was prepared through further carbonization and sulfurization. The samples were characterized and evaluated by X-ray powder diffractometer (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and electrochemical techniques. The results indicate that when the size of Co-MOF is less than 300 nm, the cubic structure framework easily collapses to form the spherical structure during the carbonization process. The catalytic activity of Co@NC is size-dependent; Co/CoS 2 @NC exhibited the best performance among the series, with an overpotential of 188 mV for HER and 349 mV for OER at a current density of 10 mA cm−2. This work provides experimental guidance for the design and synthesis of low-cost, efficient, and robust Co-based electrocatalysts. • With Co-MOF cubic nanoparticles as the precursor, Co/CoS 2 @NC was prepared through carbonization and sulfurization. • Co/CoS 2 @NC exhibited the best performance among the series. • The catalytic activity of Co@NC is size-dependent. • This work provides a guidance for the design and synthesis of low-cost, efficient, and robust Co-based electrocatalysts. [ABSTRACT FROM AUTHOR]

Solar‐driven transfer hydrogenation of unsaturated bonds has received considerable attention in the research area of sustainable organic synthesis; however, water, the ultimate green source of hydrogen, has rarely been investigated due to the high barrier associated with splitting of water molecules. We report a carbon‐nitride‐supported palladium single‐atom heterogeneous catalyst with unparalleled performance in photocatalytic water‐donating transfer hydrogenation compared to its nanoparticle counterparts. Isotopic‐labeling experiments and operando nuclear magnetic resonance measurements confirm the direct hydrogenation mechanism using in situ‐generated protons from water splitting under visible‐light irradiation. Density functional theory calculations attribute the high activity to lower barriers for hydrogenation, facilitated desorption of ethylbenzene, and facile hydrogen replenishment from water on the atomic palladium sites. [ABSTRACT FROM AUTHOR]

Solar‐driven transfer hydrogenation of unsaturated bonds has received considerable attention in the research area of sustainable organic synthesis; however, water, the ultimate green source of hydrogen, has rarely been investigated due to the high barrier associated with splitting of water molecules. We report a carbon‐nitride‐supported palladium single‐atom heterogeneous catalyst with unparalleled performance in photocatalytic water‐donating transfer hydrogenation compared to its nanoparticle counterparts. Isotopic‐labeling experiments and operando nuclear magnetic resonance measurements confirm the direct hydrogenation mechanism using in situ‐generated protons from water splitting under visible‐light irradiation. Density functional theory calculations attribute the high activity to lower barriers for hydrogenation, facilitated desorption of ethylbenzene, and facile hydrogen replenishment from water on the atomic palladium sites. [ABSTRACT FROM AUTHOR]

The mechanism study of redox mediator to transfer the photogenerated electrons is extremely desirable for artificial Z-scheme photocatalytic systems. Here we find that the α-Fe 2 O 3 exposed by {012} and {104} facets can facilitate the reduction of IO 3 − , which results in increasing the activity of photocatalytic water oxidation significantly. By employing NaIO 3 as an electron acceptor, the O 2 evolution activity (309.4 μmol h −1 g −1 ) of α-Fe 2 O 3 photocatalyst mainly exposed by {012} and {104} facets is 84 times higher than that (3.68 μmol h −1 g −1 ) of α-Fe 2 O 3 mostly exposed by {101} and {111} planes. We anticipate that the findings in this work may open the door for further development of enhanced Z-scheme photocatalytic systems. [ABSTRACT FROM AUTHOR]

Doping has been widely used to engineer efficient photocatalysts for the water-splitting process in energy conversion and storage systems. Although composition tuning through heteroatom doping is one of the strategies to enhance photoactivity, the origin of the increased activity by doping remains unclear and most illustrations of its role fall in the band engineering area. Herein, it is reported that the rhodium dopants on the surface of Zn2GeO4, which affect the band structure negligibly, can act as active sites for water splitting. As a result, the Rhδ+/Zn2GeO4 photocatalyst demonstrates excellent stability for up to 460 days and significant enhancement of the photocatalytic activity to that of the undoped photocatalyst. The findings in this work may open the door for a rethink of the detailed principles of dopants in photocatalysis, and highlight a feasible route to fabricating efficient photocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • Operando NMR combined with gas-probe method was used to study active sites transfer under the metal-support interaction. • The photocatalytic conversion efficiency of pure TiO 2 decreased, while that of Pt/TiO 2 was unaffected in gas conditions. • After loading metal-Pt, active sites changed from TiO 2 surface to Pt/TiO 2 interface. Recently metal-support interaction (MSI) has attracted considerable attention in photocatalysis. Some studies emphasize the importance of active sites on photocatalysts; however, there are no reports on site changes under MSI in real reactive conditions. Herein, an operando nuclear magnetic resonance technique was proposed to study such site changes on anatase TiO 2 and Pt/TiO 2 , through a gas-probe method, in CH 3 OH reforming. The photocatalytic oxidation efficiency of CH 3 OH by pure TiO 2 decreased immensely under extra-gas conditions, while that by Pt/TiO 2 was unaffected. The surface of pure TiO 2 were occupied by injected gas molecules, making CH 3 OH inaccessible to active sites. However, in Pt/TiO 2 , CH 3 OH adsorption sites changed from TiO 2 surface to metal-Pt/TiO 2 interface as confirmed by H 2 gas-probe experiments. This study provides a deeper understanding of active sites transfer by MSI and leverages the gas-probe method for its detection to guide the development of technology to test active-site positions in heterogeneous catalysts. [ABSTRACT FROM AUTHOR]

Nano-structuring and metal-support interactions are effective methods to improve the electrocatalytic activity of heterogeneous catalysis. In this study, we synthesized nitrogen-doped porous carbon substrates by using a SiO 2 -protected calcination strategy with ZIF-8 as a precursor. The experimental results revealed the prepared porous nitrogen-doped carbon (PNC) to have high dispersion, large specific surface area, and rich pore structure, allowing high exposure of active sites. The carbon support showed optimum characteristics to deposit precious metals with small particle sizes. X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) showed that the N groups on the PNC substrates served as coordination sites for Ru, allowing the formation of ultrafine nanoclusters. The Ru clusters showed good metal dispersion, exposing more active sites and improving the utilization of the precious metal. At a current density of 10 mA/cm2, Ru/PNC showed a minimum overpotential of 40 mV. This work provided a simple and effective method for the preparation of excellent carbon substrates and the synthesis of metal clusters with small particle sizes. N-doped porous carbon (PNC) was synthesized by a SiO 2 -protected calcination strategy by using ZIF-8 as precursor. Compared with Ru/NC, the HER catalytic performance of Ru/PNC catalysts with Ru clusters has been significantly improved. [Display omitted] • Ru nanoclusters was prepared by the EG microwave-assisted method. • N-doped porous carbon was synthesized by a SiO 2 -protected calcination strategy. • Ru/PNC catalyst showed excellent HER-catalytic performance in acidic media. [ABSTRACT FROM AUTHOR]

Copper‐based materials are efficient electrocatalysts for the conversion of CO2 to C2+ products, and most these materials are reconstructed in situ to regenerate active species. It is a challenge to precisely design precatalysts to obtain active sites for the CO2 reduction reaction (CO2RR). Herein, we develop a strategy based on local sulfur doping of a Cu‐based metal–organic framework precatalyst, in which the stable Cu−S motif is dispersed in the framework of HKUST‐1 (S‐HKUST‐1). The precatalyst exhibits a high ethylene selectivity in an H‐type cell with a maximum faradaic efficiency (FE) of 60.0 %, and delivers a current density of 400 mA cm−2 with an ethylene FE up to 57.2 % in a flow cell. Operando X‐ray absorption results demonstrate that Cuδ+ species stabilized by the Cu−S motif exist in S‐HKUST‐1 during CO2RR. Density functional theory calculations indicate the partially oxidized Cuδ+ at the Cu/CuxSy interface is favorable for coupling of the *CO intermediate due to the modest distance between coupling sites and optimized adsorption energy. [ABSTRACT FROM AUTHOR]

Copper‐based materials are efficient electrocatalysts for the conversion of CO2 to C2+ products, and most these materials are reconstructed in situ to regenerate active species. It is a challenge to precisely design precatalysts to obtain active sites for the CO2 reduction reaction (CO2RR). Herein, we develop a strategy based on local sulfur doping of a Cu‐based metal–organic framework precatalyst, in which the stable Cu−S motif is dispersed in the framework of HKUST‐1 (S‐HKUST‐1). The precatalyst exhibits a high ethylene selectivity in an H‐type cell with a maximum faradaic efficiency (FE) of 60.0 %, and delivers a current density of 400 mA cm−2 with an ethylene FE up to 57.2 % in a flow cell. Operando X‐ray absorption results demonstrate that Cuδ+ species stabilized by the Cu−S motif exist in S‐HKUST‐1 during CO2RR. Density functional theory calculations indicate the partially oxidized Cuδ+ at the Cu/CuxSy interface is favorable for coupling of the *CO intermediate due to the modest distance between coupling sites and optimized adsorption energy. [ABSTRACT FROM AUTHOR]

• In-situ nitrogen doping was achieved by one-step method, a series of Fe M (M = Pt, Pd, Ru, Rh) alloy electrocatalyst NPs with N-doped carbon coatings (Fe M @CN) was synthesized based on a noble metal doped Fe-MOF. • The optimal FePt@CN electrocatalyst demonstrates high electrocatalytic performance in an acidic electrolyte, with low overpotential, high mass activity, and excellent catalytic stability. • The optimal FeRu@CN electrocatalyst obtains an unexpectedly low overpotential of 18 mV in an alkaline electrolyte, which results in a current density of 10 mA cm−2 that is even better than a commercial Pt/C electrocatalyst with 20 wt% Pt loading. • The systematic study presented herein demonstrates that electrocatalysts suitable for different electrolytes can be found in the same alloy system, provides a universal and simple method for synthesizing transition and noble metal alloy electrocatalyst NPs that provides promising prospects for application in industrial electrolysis systems. The alloy catalyst formed by transition metal and a small amount of noble metal has become the most promising substitute for M-based (M = Pt, Pd, Ru, Rh) catalyst. However, due to the direct exposure of the metal core to the electrolyte, it is vulnerable to corrosion and oxidation, which in turn reduces the catalytic stability and is becoming a major obstacle to sustainable hydrogen production. The present work addresses this issue by developing a one-step immersion-adsorption-pyrolysis strategy for synthesizing FeM alloy nanoparticles with N-doped carbon coatings (FeM@CN) for use as electrocatalysts in the HER. The deliberately designed metal-organic framework material was used as the precursor of catalyst synthesis to achieve the carbon coatings and simultaneously the heteroatom in-situ doping for the alloy nanoparticles. The optimal FePt@CN demonstrates excellent catalytic stability and HER activity in an acidic electrolyte medium. The reactions obtain a small overpotential of 28 mV to achieve current densities of 10 mA cm−2, which are comparable to a high-performance commercial Pt/C electrocatalyst with a much higher Pt loading. The FeRu@CN also demonstrates an outstanding performance with an overpotential of only 18 mV to achieve a current density of 10 mA cm−2 in an alkaline medium. In-situ nitrogen doping was achieved by one-step method, a series of Fe M (M = Pt, Pd, Ru, Rh) alloy electrocatalyst NPs with N-doped carbon coatings (Fe M @CN) was synthesized based on a noble metal doped Fe metal organic framework. The systematic study presented herein demonstrates that electrocatalysts suitable for different electrolytes can be found in the same alloy system. [Display omitted] [ABSTRACT FROM AUTHOR]

Graphitic carbon nitride (g-C3N4) has been identified as a promising material for photocatalytic hydrogen (H2) production, but it shows a low activity. Herein, g-C3N4 doped with a benzene ring (B–CNx) was synthesized via a simple thermal polycondensation method, exhibits 5.4 times higher H2 evolution rate than the pristine one, and achieves a high apparent quantum yield of 4.11% at 420 nm. [ABSTRACT FROM AUTHOR]

Operando NMR has been exploited to probe the effects of photon flux and wavelength on photocatalytic reforming of methanol. • Operando NMR technique can be used to study the CH 3 OH photochemistry process. • CH 3 OH oxidation reaction could be enhanced by photon flux. • Photo energy had different effects on CH 3 OH photoreactions for TiO 2 and Pd/TiO 2. • SPR of the metal cocatalyst can be observed at 380 nm for the Pd/TiO 2 sample. • Operando NMR may help know the photoreactions in practical working conditions. Photocatalytic decomposition of water for hydrogen generation is a promising way to obtain clean energy sources, and photon flux together with photon energy play particularly important roles in photocatalytic reactions. However, a study of their effects under real conditions is still limited, thus leaving a gap in our understanding. Herein, an operando NMR technique was proposed to systematically study the effects of photon flux and photon energy on TiO 2 and Pd/TiO 2 -based photocatalytic methanol reforming reactions by changing the irradiation wavelength from 350 to 400 nm. Experimental results showed that the productivity of the methanol oxidation reaction can be obviously influenced by photon flux for the pure TiO 2 and Pd/TiO 2 sample, but longer wavelengths (lower photon energy) can slow down the reaction. Meanwhile, on the Pd/TiO 2 catalyst a significantly enhanced activity in CH 3 OH oxidation was found at the irradiation with the wavelength of 380 nm, which activity in CH 3 OH oxidation is even higher than that observed under the irradiation with the wavelength of 365 nm. This enhanced oxidation activity can be attributed to the surface plasmon resonance of the cocatalyst. [ABSTRACT FROM AUTHOR]

Operando NMR combined with the DFT calculations has been exploited to probe the crucial role of the bulk H 2 O in the CH 3 OH heterogeneous photochemistry processes on the surface of rutile-TiO 2. • Bulk H 2 O can significantly affect the CH 3 OH reforming products. • The participation ways of bulk H 2 O can vary from H 2 O molecule to H-atom. • The productivities of CH 3 OH reforming products vary with H 2 O concentration. • Operando NMR can be used to probe the kinetics of the CH 3 OH photocatalysis. Solid-liquid heterogeneous catalysis reactions play key roles in industrial catalytic reactions, throughout pollution control, fuel cell, methanol reforming and so on. But, few operando techniques have been performed to track the complex reaction processes, especially those in bulk liquid environment containing two or more liquid reactants, thus leaving a gap in our understanding of the reaction mechanisms deep into the working conditions. Here, we demonstrate an approach, using operando nuclear magnetic resonance (NMR) to probe the dynamics and kinetics of the methanol heterogeneous photochemistry processes in liquid condition with and without bulk water (H 2 O). It shows that not only can bulk H 2 O affect the types of methanol reforming products, but also its participation way can vary from H 2 O molecule to H-atom. Furthermore, the productivities of the main products - methylene glycol (HOCH 2 OH) and hemiacetal (CH 3 OCH 2 OH) – show different dependency on the H 2 O concentration, which is further supported by the density functional theory calculations (DFT). The operando NMR method opens up exciting opportunities for the mechanism studies of heterogeneous catalysis reaction in bulk liquid. [ABSTRACT FROM AUTHOR]

The search of efficient and stable photocatalysts for the evolution of hydrogen from water using solar energy is of great importance for material science today. Limited by the relatively inferior stability of oxynitrides, the availability of these visible-light-response materials in photocatalysis is still far below what is expected. Here we report a novel oxynitride Ce 0.3 Zr 0.7 O 1.88 N 0.12 as an efficient and stable H 2 -evolving photocatalyst under visible light irradiation, which can further enable overall water splitting by coupling with an O 2 -evolving photocatalyst via Z-scheme. Experimental and theoretical results together reveal that the origin of the excellent activity and stability of Ce 0.3 Zr 0.7 O 1.88 N 0.12 photocatalyst can be attributed to the improved separation rate of photoexcited charge carriers by surface and sub-surface oxygen vacancies. The present study provides a strategy to engineer efficient and stable photocatalysts, and the oxynitride mentioned above could act as a promising candidate of H 2 -evolving photocatalyst for designing a prominent Z-scheme photocatalytic system. [ABSTRACT FROM AUTHOR]

Cadmiun sulfide (CdS) is considered as a promising semiconductor photocatalyst for its outstanding light absorbance and photoinduced charge separation, but it suffers from severe photocorrosion, mainly due to the sluggish kinetics of holes transfer. In this work, we introduce the strong local Coulomb attraction, which is demonstrated via the in situ K-edge X-ray absorption near edge (XANES) analysis, to accelerate the migration of holes for long-term photocatalytic activity. As a proof-of-concept sample, the hole-attraction Fe 2 O 3 /CdS nanorods evidence an outstanding stability of at least 6 days without obvious deactivation, and feature with an excellent H 2 evolution rate of 20.7 mmol g −1 h −1 . Moreover, this Coulomb attraction strategy can be leveraged to enhance the photocatalytic performance of Zn 0.5 Cd 0.5 S, indicating the wide application of the strategy. [ABSTRACT FROM AUTHOR]

Metallic Ni3P/Ni can be used as a co-catalyst to replace noble metal Pt for efficient photocatalytic hydrogen evolution, due to its excellent trapping-electron ability. The applications of metallic Ni3P/Ni co-catalyst on CdS, Zn0.5Cd0.5S, TiO2 (Degussa P25) and g-C3N4 are further confirmed, indicating its versatile applicability nature like Pt. [ABSTRACT FROM AUTHOR]

Semiconductor photocatalysts are hardly employed for overall water splitting beyond 700 nm, which is due to both thermodynamic aspects and activation barriers. Metallic materials as photocatalysts are known to overcome this limitation through interband transitions for creating electron-hole pairs; however, the application of metallic photocatalysts for overall water splitting has never been fulfilled. Black tungsten nitride is now employed as a metallic photocatalyst for overall water splitting at wavelengths of up to 765 nm. Experimental and theoretical results together confirm that metallic properties play a substantial role in exhibiting photocatalytic activity under red-light irradiation for tungsten nitride. This work represents the first red-light responsive photocatalyst for overall water splitting, and may open a promising venue in searching of metallic materials as efficient photocatalysts for solar energy utilization. [ABSTRACT FROM AUTHOR]

Semiconductor photocatalysts are hardly employed for overall water splitting beyond 700 nm, which is due to both thermodynamic aspects and activation barriers. Metallic materials as photocatalysts are known to overcome this limitation through interband transitions for creating electron-hole pairs; however, the application of metallic photocatalysts for overall water splitting has never been fulfilled. Black tungsten nitride is now employed as a metallic photocatalyst for overall water splitting at wavelengths of up to 765 nm. Experimental and theoretical results together confirm that metallic properties play a substantial role in exhibiting photocatalytic activity under red-light irradiation for tungsten nitride. This work represents the first red-light responsive photocatalyst for overall water splitting, and may open a promising venue in searching of metallic materials as efficient photocatalysts for solar energy utilization. [ABSTRACT FROM AUTHOR]

The development of low-Pt catalysts is important for the large-scale application of Pt-based catalysts. Catalytic reactions mainly occur on the surface or interface of a material, and thus the surface properties of the catalyst will strongly affect their catalytic activity; this phenomenon has attracted widespread attention. Here, a series of Pt NPs with different chemical states and particle sizes were obtained by changing the light source wavelength, light time, and other conditions of light deposition synthesis. The Pt-TiO 2 catalyst has excellent potential in both photocatalytic hydrogen evolution (4.5 mmol·g−1·h−1) and electrocatalytic hydrogen evolution (26 mV@10 mA cm−2). We also found that the photocatalytic activity is more sensitive to the chemical state of Pt and that reducing the catalyst size can improve the electrocatalytic activity. This work not only provides a green and effective method to adjust the chemical state of precious metals on metal oxides but also helps to understand the impact of surface states on the catalytic process. A series of Pt NPs with different chemical states and sizes were embedded in TiO 2 (B) via a modified photochemical reduction method. The optimized Pt-TiO 2 (B) bifunctional catalyst exhibited excellent p-HER and e-HER catalytic activity. [Display omitted] • A series of Pt NPs with different chemical states and particle sizes were obtained by a photochemical strategy. • The optimized Pt-TiO 2 catalyst has excellent potential in both p-HER (4.5 mmol g−1 h−1) and e-HER (26 mV@10 mA cm−2). • The p-HER is more sensitive to the chemical state of Pt, and reducing the catalyst size improves the e-HER. • This work provides a new idea to promote catalytic activity by adjusting the catalyst's state and size. [ABSTRACT FROM AUTHOR]

Fluorine-doped hierarchical porous single-crystal rutile TiO2 nanorods have been synthesized through a silica template method, in which F− ions acts as both n-type dopants and capping agents to make the isotropic growth of the nanorods. The combination of high crystallinity, abundant surface reactive sites, large porosity, and improved electronic conductivity leads to an excellent photoelectrochemical activity. The photoanode made of F-doped porous single crystals displays a remarkably enhanced solar-to-hydrogen conversion efficiency (≈0.35 % at −0.33 V vs. Ag/AgCl) under 100 mW cm−2 of AM=1.5 solar simulator illumination that is ten times of the pristine solid TiO2 single crystals. [ABSTRACT FROM AUTHOR]

Brassinosteroids play diverse roles in plant growth and development. Plants deficient in brassinosteroid (BR) biosynthesis or defective in signal transduction show many abnormal developmental phenotypes, indicating the importance of both BR biosynthesis and the signaling pathway in regulating these biological processes. Recently, using genetics, proteomics, genomics, cell biology, and many other approaches, more components involved in the BR signaling pathway were identified. Furthermore, the physiological, cellular, and molecular mechanisms by which BRs regulate various aspects of plant development, are being discovered. These include root development, anther and pollen development and formation, stem elongation, vasculature differentiation, and cellulose biosynthesis, suggesting that the biological functions of BRs are far beyond promoting cell elongation. This review will focus on the up-to-date progresses about regulatory mechanisms of the BR signaling pathway and the physiological and molecular mechanisms whereby BRs regulate plant growth and development. [ABSTRACT FROM PUBLISHER]

• The carboxyl group with electron-withdrawing effect was grafted on the surface of graphite carbon nitride. • The electron-withdrawing effect can promote the separation and migration of carriers to improve photocatalytic performance. • The performance achieved 52 times enhancement with an apparent quantum yield of 15.7 % at 420 nm. Graphitic carbon nitride (g-C 3 N 4) has recently emerged as a promising candidate for photocatalytic hydrogen evolution, but only showed limited activity owing to its sluggish photogenerated carriers separation and migration. Herein, the carboxyl-functionalized g-C 3 N 4 (O CN) was synthesized by a grafting post-treatment method to alleviate the negative influences from this intrinsic drawback. As a result, the surface carboxyl groups greatly improve charge carrier dynamics to suppress carriers recombination via the driving force originated from its electron-withdrawing effects. The resultant O CN exhibits 52 times higher hydrogen evolution rate than the pristine, and possesses a high apparent quantum yield (AQY) of 15.7 % at 420 ± 15 nm. This work deepens the understanding of the surface group related modifications for photocatalytic materials, further providing a promising approach for rational design of photocatalysts with highly efficient solar energy conversion. [ABSTRACT FROM AUTHOR]

The development of novel, noble metal-free semiconductor catalysts with high efficiency is of great importance for the degradation of organic compounds. Among them, amorphous materials have been extensively studied for their unique and commercially useful properties. Here, a completely amorphous, noble metal-free photocatalyst C3N4ZnxOy (x, y = 0.32–1.10) was successfully synthesized from urea and ZnO by a simple high-temperature polymerization method. As the Zn content increased, the short-range ordered structures of the amorphous samples were still retained, as revealed by XPS, FTIR, and ssNMR. Meanwhile, the -CN3 structures were observed to be gradually destroyed, which may make the amorphous state more favorable for photocatalytic reactions. Compared with g-C3N4, the amorphous samples showed significantly reduced intensities in the photoluminescence spectra, indicating that the recombination rate of the photo-generated charge carriers was greatly reduced. It was confirmed that the optimized sample (C3N4Zn0.61O0.61) achieved a photocatalytic efficiency of 86.1% in the degradation of tetracycline hydrochloride under visible light irradiation within 1 h. This is about 2 times higher than that of both g-C3N4 and ZnO. This study emphasizes the importance of the amorphous structure in photocatalytic reactions, and this synthetic strategy may provide an effective model for designing other novel catalysts. [ABSTRACT FROM AUTHOR]