The synthesis of facet-controlled structures with precise morphology and exposed reactive surface is one of the key research challenges. We effectively endeavoured to obtain the monodisperse octahedral bismuth vanadate microcrystals with exposed {1 0 1},{2 0 0},{3 1 2} and {0 2 1} dominant facets through an optimized sonochemical assisted hydrothermal process. A pulse sonication (5-s ON and 2-s OFF cycle, 21 W ultrasonic power and 20 kHz ultrasonic frequency) for 30 mins followed by 1 h hydrothermal treatment was found to yield the preferred octahedral morphology. The microscopic and X-ray analysis suggested a potent role of ultrasonic waves for the initial seed growth and its evolution into a well-defined monodisperse microcrystals. The density functional theory (DFT) calculations revealed strongly localized bandgap states with a bandgap of ~2.47 eV. The PEC measurements for water oxidation demonstrated the efficacy of these microcrystals as photoanode. Notably, the optimized octahedral BiVO₄ microstructure exhibited a superior performance as evident from photocurrent density ~0.9 mAcm⁻² at 1.23 V vs. RHE and %IPCE value of ~22% compared to analogous photoanodes under visible light irradiation.

具有精确的形态和暴露的反应表面的刻面控制结构的合成是关键的研究挑战之一。我们通过优化的声化学辅助水热工艺有效地努力获得了具有{1 0 1}，{2 0 0}，{3 1 2}和{0 2 1}显性面暴露的单分散八面体钒酸铋微晶。发现脉冲声处理（5-s ON和2-s OFF周期，21 W超声功率和20 kHz超声频率）持续30分钟，然后进行1 h水热处理，产生了较好的八面体形态。显微镜和X射线分析表明，超声波对于种子的初始生长及其演变为定义明确的单分散微晶具有强大作用。密度泛函理论（DFT）计算显示带隙为〜2的强局部带隙状态。47 eV。用于水氧化的PEC测量证明了这些微晶作为光阳极的功效。值得注意的是，优化的八面体BiVO与在可见光照射下的类似光阳极相比，在1.23 V vs. RHE时的光电流密度〜0.9 mAcm ^-2和〜22％的％IPCE值下可见，_4个微结构表现出优异的性能。