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[Display omitted] In the process of photocatalytic ammonia synthesis, efficient activation of nitrogen molecules constitutes a fundamental challenge. During the N 2 activation, the close interdependence between the acceptance and donation of electron results in their mutual limitation, leading to high energy barrier for N 2 activation and unsatisfactory photocatalytic performance. This work decoupled the electron acceptance and donation processes by constructing Fe-Bi dual active sites, resulting in enhancing N 2 activation through the high electron trapping ability of Fe3+ and strong electron donating ability of Bi2+. The photocatalytic nitrogen reduction efficiency of 3%Fe/Bi 2 O 2.33 (118.71 μmol g cat −1h−1) is 5.3 times that of Bi 2 O 2.33 (22.41 μmol g cat −1h−1). In-situ Fourier transform infrared (In situ FTIR) spectroscopy and density functional theory (DFT) calculations manifest that Fe3+-Bi2+ dual active sites work together to promote nitrogen adsorption and activation, and the reaction path is more inclined toward alternate hydrogenation path. N 2 adsorption and activation properties are optimized by heteronuclear bimetallic active sites, which offers a new way for the rational design of nitrogen-fixing photocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] Hydrogen spillover effects will significantly improve the activity of photocatalytic hydrogen evolution reactions (HER), while their introduction and optimization require the construction of an excellent metal/support structure. In this study, we have synthesized Ru/TiO 2-x catalysts with controlled oxygen vacancy (OVs) concentrations using a simple one-pot solvothermal method. The results show that Ru/TiO 2-x3 with the optimal OVs concentration exhibits an unprecedentedly high H 2 evolution rate of 13604 μmol·g−1·h−1, which was 45.7 and 2.2 times higher than that of TiO 2-x (298 μmol·g−1·h−1) and Ru/TiO 2 (6081 μmol·g−1·h−1). Controlled experiments, detailed characterizations, and theoretical calculations have revealed that the introduction of OVs on the carrier contributes to the hydrogen spillover effect in the metal/support system photocatalyst and that the process of hydrogen spillover in this system can be optimized by modulating the OVs concentration. This study proposes a strategy to decrease the energy barrier of hydrogen spillover and enhance photocatalytic HER activity. Moreover, it investigates the effect of OVs concentration on the hydrogen spillover effect in the photocatalytic metal/supports system. [ABSTRACT FROM AUTHOR]

With Fe3+ as both the morphology-controlling agent and dopant, Fe-doped NiS 2 microcrystals with the exposed chemically stable {0 0 1} facets were synthesized hydrothermally for electrocatalytic OER. After the electrocatalytic activation, the iron-rich surface transformed into active Fe-doped nickel oxyhydroxide, while the inner {0 0 1}-oriented NiS 2 retained, endowing the catalysts with high OER activity and long-term stability. [Display omitted] Developing high-performance electrocatalysts with favorable phase, surface structure and electronic structure for oxygen evolution reaction (OER) is crucial for efficient electrocatalytic water splitting. With Fe3+ ions as both dopant and morphology-controlling agent, Fe-doped NiS 2 microcrystals with the exposed chemically stable {0 0 1} facets were synthesized hydrothermally for electrocatalytic OER. The initial electrocatalytic OER activation processes led to the conversion of iron-rich surface layers of the NiS 2 microcrystals into Fe-doped Ni (oxy)hydroxide as the shell and the residual inner of the NiS 2 microcrystals as the core. Such Fe-doped NiS 2 microcrystals with the derived core/shell structure only required a small OER overpotential of 277 mV to reach an electrochemical current density of 10 mA/cm2, and showed a good stability in a more than 20 h duration test almost without overpotential increase. [ABSTRACT FROM AUTHOR]

New insight of introducing new organic compounds for the efficient photogenerated charge separation is vitally important for the current solar energy conversion. Herein, (2Z,2′Z)-4,4′-(anthracene-2,6-diylbis(azanediyl))bis(4-oxobut-2-enoic acid) (ADA)/TiO 2 composite thin film is fabricated through the wet-impregnation strategy, which exhibits excellent photoelectrochemical performance (PEC). A combined study of ultraviolet-visible absorption spectra, scanning Kelvin probe maps, electrochemical and photoelectrochemical measurements reveals that the ADA/TiO 2 composite with narrow bandgap of 2.42 eV extends the photo response to the visible light region. The photocurrent generated by the optimal ADA/TiO 2 is 2.5 times higher than that of the pristine TiO 2 . The result is attributed to the broader light absorption range and the separation of photoelectrons and holes prompted by ADA. Moreover, the high stability of the ADA/TiO 2 composite favors the practical application. The present work may offer a promising strategy for the low-cost PEC cell in the clean solar hydrogen production. [ABSTRACT FROM AUTHOR]

Tunable active sites emerged over Cu-ZSM-5 catalysts via modulating Cu contents showed excellent catalytic performance in methane to methanol conversion. The generation of CH 3 OH was operated under the synergetic effect of the Cu x O y NPs and Cu–OH motif, in which multiple mechanisms via methyl intermediates and free radicals (•OH/•OOH) in the liquid phase. [Display omitted] • Methane oxidation toward methanol are achieved at considerable productivity of 15975.73 μmol/g cat /h. • Tunable active species (Cu1+/0, Cu x O y nanoparticles, Cu–OH motif) emerged via modulating Cu contents. • The co-existing Cu x O y nanoparticles and Cu–OH motif synergistically promote methanol generation. • Reactive oxygen species produced by H 2 O 2 take part in the reaction in a parallel way. Copper decorated zeolites are promising candidates for the partial oxidation of methane to generate methanol with elevated energy density, nevertheless, the modulation and possible synergism between multiple Cu active sites still need to be delved in depth. Here, ZSM-5 catalysts with modulated Cu motifs were proposed using copper oxysalts as precursors through a calcination process. By modifying the contents of copper oxysalts precursors, the Cu active sites varied, and a unique M shaped trend of CH 3 OH productivity emerged. Attributed to the synergetic effects of Cu x O y nanoparticles (adsorbing CH 4 and generating *OCH 3 species) and Cu–OH motif (binding CH 4 and forming Si···CH 3), a maximum CH 3 OH yield of 15975.73 μmol/g cat /h (with CH 3 OOH yield of 2155.59 μmol/g cat /h) and methyl oxygenates selectivity up to 72.79 % could be achieved. This work paved an efficient, low cost, and succinct way for the manufacture of catalysts with tunable active sites and high performance over methane to methanol conversion. [ABSTRACT FROM AUTHOR]

The confined growth of ultra-thin and nanometer-sized FeOOH/CoP on the rough pore wall of self-synthesized hierarchically porous Ni foam support show improved OER activity and stability. [Display omitted] Self-supported electrodes, featuring abundant active species and rapid mass transfer, are promising for practical applications in water electrolysis. However, constructing efficient self-supported electrodes with a strong affinity between the catalytic components and the substrate is of great challenge. In this study, by combining the ideas of in-situ construction and space-confined growth, we designed a novel self-supported FeOOH/cobalt phosphide (CoP) heterojunctions grown on a carefully modified commercial Ni foam (NF) with three-dimensional (3D) hierarchically porous Ni skeleton (FeOOH/CoP/3D NF). The specific porous structure of 3D NF directs the confined growth of FeOOH/CoP catalyst into ultra-thin and small-sized nanosheet arrays with abundant edge active sites. The active FeOOH/CoP component is stably anchored on the rough pore wall of 3D NF support, leading to superior stability and improved conductivity. These structural advantages contributed to a highly facilitated oxygen evolution reaction (OER) activity and enhanced durability of the FeOOH/CoP/3D NF electrode. Herein, the FeOOH/CoP/3D NF electrode afforded a low overpotential of 234 mV at 10 mA cm−2 (41 mV smaller than FeOOH/CoP grown on unmodified Ni foam) and high stability for over 90 h, which is among the top reported OER catalysts. Our study provides an effective idea and technique for the construction of active and robust self-supported electrodes for water electrolysis. [ABSTRACT FROM AUTHOR]

A high-performance K-NH 4 V 4 O 10 (K-NVO) cathode with K+ doping was synthesized successfully through one-step hydrothermal method, which exhibits lower barriers for Zn2+ diffusion and superior stability, leading to excellent electrochemical performance. [Display omitted] Aqueous zinc-ion batteries (AZIBs), defined by low expenses, superior safety, and plentiful reserves, demonstrate tremendous development potential in energy storage systems at the grid scale. Whereas the cathode instability and the limited diffusion of Zn2+ have impeded the development of AZIBs. Herein, a high-performance K-NH 4 V 4 O 10 (K-NVO) cathode with K+ doping synthesized successfully through one-step hydrothermal approach. Experiments and density functional theory (DFT) calculations indicate that K-NVO has Zn2+ diffusion pathways with lower barriers for smoother transport, and lower formation energy. The combination of the rapid Zn2+ diffusion and the stable structure results in outstanding electrochemical performance of K-NVO as demonstrated in tests. K-NVO cathode achieves a specific capacity of 406 mAh g−1 at 0.2 A g−1, maintains satisfactory cyclic stability with 81.6 % capacity retention after 1000 cycles at 5 A g−1, and possesses a high energy density of 350.9 Wh kg−1. Furthermore, confirmation of the zinc storage mechanism in K-NVO was carried out through Ex situ tests, such as XRD and XPS. This research contributes a unique perspective to the formulation of high-performance cathode materials for AZIBs. [ABSTRACT FROM AUTHOR]

[Display omitted] Given their plentiful reserves, impressive safety features, and economical pricing, aqueous zinc − ion batteries (ZIBs) have positioned themselves as strong competitors to lithium − ion batteries. Yet, the scarcity of available cathode materials poses a challenge to their continued development. In this study, a V 2 O 5 /V 6 O 13 heterostructure has been synthesized using a one − pot hydrothermal approach and employed as the cathode material for ZIBs. As evidenced by both experimental and theoretical findings, V 2 O 5 /V 6 O 13 heterostructure delivers a rapid electrons and ions diffusion kinetics promoted by the stable interface and strong electronic coupling with significant charge transfer between V 2 O 5 and V 6 O 13 , as well as a stable interface achieved by adjusting V − O bond length. Consequently, the optimized V 2 O 5 /V 6 O 13 heterostructure cathode of ZIBs demonstrates exceptional capacity (338 mAh g−1 at 0.1 A g−1), remarkable cycling stability (92.96 % retained after 1400 cycles at 1 A g−1). Through comprehensive theoretical calculations and ex situ characterization, the kinetic analysis and storage mechanism of Zn2+ are thoroughly investigated, providing a solid theoretical foundation for the advancement of novel V − based cathode materials aimed at enhancing the performance of ZIBs. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Herein, the hierarchical nickel molybdate@reduced graphene oxide@nickel aluminum layered double hydroxides (NiMoO 4 @rGO@NiAl-LDHs) architecture assembled from well-aligned nanosheets is successfully constructed on Ni-foam through a three-step strategy. For the first time, ultrathin graphene nanosheets are introduced by a novel spraying process to avoid the stack. NiAl-LDHs is prepared via situ growth procedure in which NiAl-LDH self-assembles on the surface of graphene to prevent graphene from aggregating, resulting in an enlarged specific surface area. Electrochemical analysis manifests that NiMoO 4 @rGO@NiAl-LDHs yields exceptional specific capacitance (3396 Fg−1 at 1 Ag−1), favorable charge/discharge rate and approving long-term stability. Furthermore, the NiMoO 4 @rGO@NiAl-LDHs//AC device delivers superior specific capacitance (137.2 Fg−1 at 1 Ag−1), high energy density (48.7 Whkg−1) associated with pleasurable power output (7987 Wkg−1). Importantly, the well-aligned NiMoO 4 @rGO@NiAl-LDHs provides a prospective conception constructing hierarchical structural materials in the area of supercapacitor. [ABSTRACT FROM AUTHOR]