Photoelectrochemical water splitting is an environmentally benign way to store solar energy. Properties such as fast charge recombination and poor charge transport rate severely restrict the use of BiVO₄ as a photoanode for photoelectrochemical water splitting and many attempts were made to improve the current performance limit of the photoanode. To address these disadvantages, a highly efficient BiVO₄/Bi₂S₃ heterojunction was fabricated applying facial anion-exchange (AE) and successive ionic layer adsorption and reaction (SILAR). The deposition of Bi₂S₃ on BiVO₄ nanoworms by both AE and SILAR was confirmed through morphological, structural, and optical analyses. The morphological analysis indicated that Bi₂S₃ grown through SILAR has relatively more crystalline-amorphous phase boundaries than Bi₂S₃ generated using the anion-exchange method. The highest photocurrent density was observed for the SILAR-coated Bi₂S₃ on BiVO₄, which is three times the value of the pristine BiVO₄ measured under 1 sun illumination (100 mW cm⁻² with Air mass (AM) 1.5 filter) in a 0.5 M Na₂SO₄ electrolyte at 1.6 V vs. RHE. In addition, the deposition of Bi₂S₃ through AE results in a twofold higher photocurrent density compared to uncoated BiVO₄. The comparison of the two cost-effective AE and SILAR methods to deposit Bi₂S₃ on BiVO₄ showed a negative shift in the flat band Mott-Schottky values, which coincides with the drifted onset potential values of the current density-voltage (J–V) curve. Furthermore, photoelectrochemical impedance spectroscopy (PEIS) analyses and band alignment studies revealed that SILAR-grown Bi₂S₃ creates an effective heterojunction with BiVO₄, which leads to an efficient charge transfer.

光电化学水分解是一种存储太阳能的环保方式。快速电荷复合和不良的电荷传输速率等特性严重限制了BiVO ₄作为光电化学水分解用光阳极的用途，并进行了许多尝试来改善光阳极的当前性能极限。为了解决这些缺点，使用面部阴离子交换（AE）和连续的离子层吸附和反应（SILAR）制备了高效的BiVO ₄ / Bi ₂ S ₃异质结。Bi ₂ S ₃在BiVO ₄上的沉积通过形态，结构和光学分析证实了AE和SILAR都具有纳米蠕虫。形态分析表明，通过SILAR生长的Bi ₂ S ₃比使用阴离子交换法生成的Bi ₂ S ₃具有相对更多的晶体-非晶相边界。在BiVO ₄上观察到了SILAR涂层的Bi ₂ S ₃的最高光电流密度，这是原始BiVO ₄在1个阳光照射下测得的值的三倍（100 mW cm ^-2的空气质量（AM）1.5滤光片）在0.5 M Na ₂ SO _4中相对于RHE的电压为1.6V。另外，与未涂覆的BiVO ₄相比，通过AE沉积Bi ₂ S ₃导致光电流密度提高了两倍。将Bi ₂ S ₃沉积在BiVO ₄上的两种具有成本效益的AE和SILAR方法的比较显示，平带Mott-Schottky值出现负向偏移，这与电流密度-电压（J –V）曲线。此外，光电化学阻抗谱（PEIS）分析和能带对准研究表明，SILAR生长的Bi ₂ S ₃与BiVO ₄形成有效的异质结，从而实现高效的电荷转移。