Photoelectrochemical water splitting is a promising approach for the carbon-free production of hydrogen using sunlight. Here, robust and efficient WO3 photoanodes for water oxidation were synthesized by the scalable one-step flame synthesis of nanoparticle aerosols and direct gas-phase deposition. Nanostructured WO3 films with tunable thickness and band gap and controllable porosity were fabricated by controlling the aerosol deposition time, concentration, and temperature. Optimal WO3 films demonstrate superior water oxidation performance, reaching a current density of 0.91 mA at 1.24 V vs. reversible hydrogen electrode (RHE) and an incident photon-to-current conversion efficiency (IPCE) of ca. 61 % at 360 nm in 0.1 m H2 SO4 . Notably, it is found that the excellent performance of these WO3 nanostructures arises from the high in situ restructuring temperature (ca. 1000 °C), which increases oxygen vacancies and decreases charge recombination at the WO3 /electrolyte interface. These findings provide a scalable approach for the fabrication of efficient photoelectrodes based on WO3 and other metal oxides for light-driven water splitting.

中文翻译：

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用于水分解的高效WO3光阳极的一步式快速可扩展火焰合成。

光电化学水分解法是利用阳光无碳生产氢的一种有前途的方法。在此，通过可扩展的一步式火焰合成纳米气溶胶和直接气相沉积法合成了用于水氧化的强大而有效的WO3光电阳极。通过控制气溶胶沉积时间，浓度和温度，制备了具有可调厚度和带隙以及可控孔隙率的纳米结构WO3薄膜。最佳的WO3膜表现出优异的水氧化性能，与可逆氢电极（RHE）相比，在1.24 V下的电流密度达到0.91 mA，入射光子至电流的转换效率约为IP。在0.1 m H2 SO4中360 nm处61％。尤其，发现这些WO3纳米结构的出色性能归因于高的原位重构温度（约1000°C），这增加了氧空位，并降低了WO3 /电解质界面处的电荷重组。这些发现为基于WO 3和其他金属氧化物的有效光电极的制造提供了可扩展的方法，用于光驱动水分解。