Perovskite BaTaO₂N has been regarded as a promising photoanode material owing to its narrow bandgap of 1.8 eV and appropriate band edge positions for photoelectrochemical (PEC) water splitting. Compared with photoanodes made with pre-synthesized BaTaO₂N particles, direct deposition of BaTaO₂N thin film on a conductive substrate is a promising way to improve the carrier transport capability. Herein, we propose a co-evaporation and nitridation method for the direct synthesis of BaTaO₂N nanoparticle film on metal substrate for PEC water splitting. The crystallinity, morphology, and defects of the synthesized BaTaO₂N nanoparticle films are varied by controlling the Ba:Ta ratios in the co-evaporated precursor films. Photoanode based on the optimized BaTaO₂N nanoparticle film achieves a photocurrent density of 4.7 mA cm⁻² at 1.23 V_RHE and a maximum applied bias photon-to-current efficiency of 1.18% at 0.83 V_RHE. Our work provides a facile method to fabricate high-crystallinity nanostructured oxynitride thin films for PEC water splitting application.

钙钛矿 BaTaO ₂ N 因其 1.8 eV 的窄带隙和适合光电化学 (PEC) 水分解的带边位置而被认为是一种很有前途的光阳极材料。与预先合成的BaTaO ₂ N 颗粒制成的光阳极相比，在导电衬底上直接沉积BaTaO ₂ N 薄膜是提高载流子传输能力的一种很有前途的方法。_{在此，我们提出了一种在金属基底上直接合成用于PEC水分解的BaTaO 2} N纳米颗粒薄膜的共蒸发和氮化方法。_{合成的 BaTaO 2}的结晶度、形貌和缺陷N 纳米颗粒薄膜通过控制共蒸发前体薄膜中的 Ba:Ta 比率来改变。基于优化的 BaTaO ₂ N 纳米颗粒薄膜的光电阳极在 1.23 V _RHE下实现了 4.7 mA cm ^{-2的光电流密度，在 0.83 V} _RHE下实现了 1.18% 的最大施加偏置光子电流效率。我们的工作提供了一种简便的方法来制造用于 PEC 水分解应用的高结晶度纳米结构氧氮化物薄膜。