钒酸铋(BVO)可用于光电化学(PEC)水解产氢, 但受限于其缓慢的表面水氧化动力学, 在电极表面修饰单一的析氧助催化剂达不到理想的性能。本工作在BVO电极表面修饰FeNiO_x助催化剂可以显著降低起始电压, 增强光电化学性能。此外, 沉积g-C₃N₄后修饰FeNiO_x助催化剂得到的光电极具有更优异的性能。厚度适合的g-C₃N₄纳米片与BVO构成Ⅱ型p-n异质结, 有效抑制了光生电子空穴的复合, 促进了电极的电荷分离。电化学测试结果表明, 沉积了g-C₃N₄后, 电极的电荷分离效率达到88.2%, 比BVO/FeNiO_x (60.6%)提升了近1.5倍。经过g-C₃N₄和FeNiO_x协同修饰的BVO/g-C₃N₄/FeNiO_x电极, 表面电荷注入效率达到了90.2%, 同时, 在1.23 V (vs. RHE)条件下光电流密度达到4.63 mA∙cm^-2, 是纯BVO (1.86 mA∙cm^-2)的2.48倍。本工作为开发制备高性能光阳极提供了一种有效的策略。

Developing low-cost, efficient, and stable photocatalysts is one of the most promising methods for large-scale solar water splitting. As a metal-free semiconductor material with suitable band gap, graphitic carbon nitride (g-C₃N₄) has attracted attention in the field of photocatalysis, which is mainly attributed to its fascinating physicochemical and photoelectronic properties. However, several inherent limitations and shortcomings—involving high recombination rate of photocarriers, insufficient reaction kinetics, and optical absorption—impede the practical applicability of g-C₃N₄. As an effective strategy, vacancy defect engineering has been widely used for breaking through the current limitations, considering its ability to optimize the electronic structure and surface morphology of g-C₃N₄ to obtain the desired photocatalytic activity. This review summarizes the recent progress of vacancy defect engineered g-C₃N₄ for solar water splitting. The fundamentals of solar water splitting with g-C₃N₄ are discussed first. We then focus on the fabrication strategies and effect of vacancy generated in g-C₃N₄. The advances of vacancy-modified g-C₃N₄ photocatalysts toward solar water splitting are discussed next. Finally, the current challenges and future opportunities of vacancy-modified g-C₃N₄ are summarized. This review aims to provide a theoretical basis and guidance for future research on the design and development of highly efficient defective g-C₃N₄.

钒酸铋是最具有光电催化应用潜力的水分解光电阳极之一, 但由于表面缓慢的动力学反应速率, 其光电催化效率仍不理想。本研究通过浸渍法在BiVO₄薄膜光阳极上负载纳米RhO₂助催化剂, 研究RhO₂负载量对BiVO₄光阳极光电催化性能的影响规律及其机理。晶粒尺寸10~25 nm的RhO₂均匀负载在颗粒尺寸100~250 nm、厚度约为400 nm的BiVO₄光阳极薄膜表面。考虑到贵金属铑的昂贵成本, RhO₂的最佳负载量为质量分数1.65%, 在偏压1.23 V (vs. RHE)、1.0 mol/L Na₂SO₃溶液中(pH8.5)AM 1.5模拟可见光照射下, 光电流密度达3.81 mA·cm^-2, 相较纯BiVO₄提升了10.58倍。在没有有机牺牲剂的条件下, 光阳极同时析出了氢气和氧气, 两者比例接近2 : 1, 产氧速率为8.22 μmol/(h·cm²)。负载RhO₂有效改善了光阳极的表面水氧化动力学, 使光生空穴更快与电解质溶液进行水氧化反应, 抑制光生载流子复合, 从而显著提升光电催化性能。另外, 负载RhO₂后, 空穴更容易从光阳极表面被有效提取到电解质溶液中, 减少其在光阳极表面积累, 从而使BiVO₄/RhO₂(1.65%)光阳极可持续稳定工作10 h以上。