Zhang Xing, Wang Chu-Ya, Wang Li-Wei, Huang Gui-Xiang, Wang Wei-Kang, Yu Han-Qing
CAS Key Laboratory of Urban Pollutant Conversion, Department of Chemistry, University of Science &Technology of China, Hefei, 230026, China.
Sci Rep. 2016 Mar 7;6:22800. doi: 10.1038/srep22800.
A series of BiOBrxI(1-x) solid solutions were explored as novel visible light-sensitive photocatalysts. These BiOBrxI(1-x) solid-solution photocatalysts grew into two-dimensional nanoplates with exposed (001) facets and possessed continuously modulated band gaps from 2.87 to 1.89 eV by decreasing the Br/I ratio. The photocatalytic activities of these samples were measured, and the samples exhibited visible light-driven activities for the degradation of Rhodamine B (RhB). In particular, BiOBr0.8I0.2 exhibited the highest activity for the degradation of RhB. This result could be attributed to the balance between the effective light absorption and adequate redox potential. Additionally, investigations into the photocatalytic mechanism showed that the photodegradation of RhB over BiOBr0.8I0.2 solid-solution photocatalysts involved direct holes oxidation, in which the reaction that dominated during photocatalysis was determined by the potential of the valence band. Furthermore, a high stability in the photocatalytic activity of BiOBr0.8I0.2 was demonstrated by the cycling photocatalytic experiment and long-term irradiation, which might offer opportunities for its practical application as a catalyst.
一系列BiOBrxI(1-x)固溶体被开发为新型可见光敏感光催化剂。这些BiOBrxI(1-x)固溶体光催化剂生长为具有暴露(001)晶面的二维纳米片，并且通过降低Br/I比，其带隙从2.87 eV连续调制到1.89 eV。测量了这些样品的光催化活性，这些样品对罗丹明B（RhB）的降解表现出可见光驱动活性。特别地，BiOBr0.8I0.2对RhB的降解表现出最高活性。该结果可归因于有效光吸收和足够氧化还原电位之间的平衡。此外，对光催化机理的研究表明，RhB在BiOBr0.8I0.2固溶体光催化剂上的光降解涉及直接空穴氧化，其中光催化过程中占主导的反应由价带电位决定。此外，循环光催化实验和长期照射证明了BiOBr0.8I0.2光催化活性的高稳定性，这可能为其作为催化剂的实际应用提供机会。
