Metal-halide perovskites have been widely investigated in the photovoltaic sector due to their promising optoelectronic properties and inexpensive fabrication techniques based on solution processing. Here we report the development of inorganic CsPbBr 3 -based photoanodes for direct photoelectrochemical oxygen evolution from aqueous electrolytes. We use a commercial thermal graphite sheet and a mesoporous carbon scaffold to encapsulate CsPbBr 3 as an inexpensive and efficient protection strategy. We achieve a record stability of 30 h in aqueous electrolyte under constant simulated solar illumination, with currents above 2 mA cm −2 at 1.23 V RHE . We further demonstrate the versatility of our approach by grafting a molecular Ir-based water oxidation catalyst on the electrolyte-facing surface of the sealing graphite sheet, which cathodically shifts the onset potential of the composite photoanode due to accelerated charge transfer. These results suggest an efficient route to develop stable halide perovskite based electrodes for photoelectrochemical solar fuel generation.

Halide perovskite CsPbBr 3 has recently gained wide interest for its application in solar cells, optoelectronics and artificial photosynthesis, but further progress is needed to develop greener and more scalable synthesis procedures and for their application in humid environments. Herein, we report a fast and convenient mechanochemical synthesis of CsPbBr 3 perovskite nanocrystals with control over crystal size and morphology. These perovskite

Pb-based halide perovskites have recently showed great potential in various applications such as solar cells, optoelectronics and photocatalysis. Despite their high performance, the Pb2+ toxicity along with poor stability hinder...

BiVO 4 has attracted wide attention for oxygen-evolution photoanodes in water-splitting photoelectrochemical devices. However, its performance is hampered by electron-hole recombination at surface states. Herein, partially oxidized two-dimensional (2D) bismuthene is developed as an effective, stable, functional interlayer between BiVO 4 and the archetypal NiFeOOH co-catalyst. Comprehensive (photo)electrochemical and surface photovoltage characterizations show that NiFeOOH can effectively increase the lifetime of photogenerated holes by passivating hole trap states of BiVO 4 ; however, it is limited in influencing electron trap states related to oxygen vacancies (V O ). Loading bismuthene on BiVO 4 photoanodes increases the density of V O that are beneficial for the oxygen evolution reaction via the formation of oxy/hydroxyl-based water oxidation intermediates at the surface. Moreover, bismuthene increases interfacial band bending and fills the V O -related electron traps, leading to more efficient charge extraction. With the synergistic interaction of bismuthene and NiFeOOH on BiVO 4 , this composite photoanode achieves a 5.8-fold increase in photocurrent compared to bare BiVO 4 reaching a stable 3.4 (±0.2) mA cm -2 at a low bias of +0.8 V RHE or 4.7(±0.2) mA cm -2 at +1.23 V RHE . The use of 2D bismuthene as functional interlayer provides a new strategy to enhance the performance of photoanodes.

Enhanced Oxygen‐Evolution Photoanodes In article number 2207136, Salvador Eslava and co‐workers demonstrate a successful design of BiVO4/bismuthene/NiFeOOH composite photoanodes for enhanced solar water oxidation. They found that bismuthene increases the density of oxygen vacancies on BiVO4, increases interfacial band bending, and fills vacancy‐related electron traps with charges, whereas NiFeOOH significantly increases surface hole concentration by passivating recombination surface states.

Water splitting in photoelectrochemical cells is a promising technology to produce solar hydrogen. Fe2TiO5 pseudobrookite with a bandgap of around 2 eV absorbs the predominant visible range of the solar spectrum and is emerging as a promising photoanode for such cells. Herein, we present Fe2TiO5 pseudobrookite-based films prepared by aerosol-assisted chemical vapor deposition and the positive impact of Zn 2+ doping in their formation and performance. Undoped and Zn 2+doped Fe2TiO5 pseudobrookite-based photoanodes were characterized by techniques such as XRD, XPS, UPS and Mott-Schottky analysis. We find that the Zn 2+ ions are preferentially incorporated in the pseudobrookite phase over a present secondary hematite (α-Fe2O3) phase. The Zn 2+ doping modifies the electronic properties of the films, increases their charge carrier concentration and upshifts their Fermi level, significantly improving their anodic photocurrent response by a factor of three. In addition, charge transfer efficiency calculations reveal that Zn 2+ doping improves both charge separation and injection efficiencies, overall demonstrating a promising approach for the design of enhanced pseudobrookite-based photoanodes.

TiO2 photoanodes with {0 1 0} facets exposed show high photoelectrochemical performance and IPCE of 100% at 350 nm.

[Ti4Mo2O8(OEt)10]2cages were used for the formation of Mo-doped TiO2photoanodes with better performance than pure TiO2.