Dissolution behaviors of a visible-light-responsive photocatalyst BiVO4: Measurements and chemical equilibrium modeling.
Dissolution behaviors of a visible-light-responsive photocatalyst BiVO4: Measurements and chemical equilibrium modeling.
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DOI：
10.1016/j.jhazmat.2022.130187
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发表时间：
2022-10
影响因子：
13.6
通讯作者：
Hongbiao Wen;Z. Pan;Xingxing Wang;Kejian Li;Qihuang Wang;Jinming Luo;Hongbo Fu;Liwu Zhang;Zimeng Wang
中科院分区：
文献类型：
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作者：
Hongbiao Wen;Z. Pan;Xingxing Wang;Kejian Li;Qihuang Wang;Jinming Luo;Hongbo Fu;Liwu Zhang;Zimeng Wang
尽管在半导体材料和器件创新方面进行了广泛的研究，但这些新材料的大部分基本水化学控制其环境危害和影响仍然知之甚少。BiVO 4一直被认为是一种很有前途的可见光响应光催化剂。然而，BiVO 4的溶度积（Ksp）和BiVO 4的非化学计量溶解的机理的理解仍然不清楚。在此，我们通过观察BiVO 4在pH 4-9范围内的非化学计量溶解，研究了BiVO 4的溶解度。结合溶解实验、吸附行为和热力学平衡计算，确定BiVO 4的Ksp为10−35.81±0.51。BiVO 4的溶解度和稳定性具有很强的pH依赖性，在pH 5附近溶解度最低，稳定性最高。此外，我们测试了光照对BiVO 4溶解的影响，光照显著增强了BiVO 4的溶解。在黑暗和光照条件下，BiVO 4固体对溶解铋的吸附是导致BiVO 4非化学计量溶解的主要原因，并可通过引入额外的表面络合反应来模拟。因此，研究结果强调了考虑光催化剂溶解的重要性，并为评估其他半导体材料的环境稳定性和风险提供了可行的方法。
Despite of the extensive research in semiconductor photocatalysis with respect to material and device innovations, much of the fundamental aquatic chemistry of those new materials that governs their environmental hazard and implications remains poorly understood. BiVO4has long been recognized as a promising visible-light-responsive photocatalyst. However, the solubility product (Ksp) of BiVO4and the mechanistic understanding of the non-stoichiometric dissolution of BiVO4remain unclear. Here, we investigated the solubility of BiVO4via the observation on its non-stoichiometric dissolution in the pH range of 4–9. Combining dissolution experiments, adsorption behavior and thermodynamic equilibrium calculations, theKspof BiVO4was determined to be 10−35.81±0.51. The solubility and stability of BiVO4were strongly pH-dependent, with the lowest solubility and highest stability near pH 5. Furthermore, we tested the effect of illumination on the dissolution of BiVO4, which was significantly enhanced by light. Under both dark and illumination conditions, adsorption of dissolved bismuth by BiVO4solids was the main reason for the non-stoichiometric dissolution of BiVO4, and could be modeled by including an additional surface complexation reaction. Thus, the results highlighted the importance of considering the dissolution of photocatalysts, and presented a feasible method to evaluate environmental stability and risks of other semiconductor materials.