Controllable Crystal Growth and Improved Photocatalytic Activity of Porous Bi<sub>2</sub>O<sub>3</sub>–Bi<sub>2</sub>S<sub>3</sub> Composite Sheets
Yuan‐Chang Liang, Yu-Hsun Chou, Bo-Yue Chen, Wei-Yang Sun
Abstract
High Resolution Image Download MS PowerPoint Slide Porous Bi 2 O 3 –Bi 2 S 3 composite sheets were constructed through a combinational methodology of chemical bath deposition and hydrothermal reaction. The Na 2 S precursor concentration in the hydrothermal solution was varied to understand the correlation between the vulcanization degree and structure evolution of the porous Bi 2 O 3 –Bi 2 S 3 composite sheets. The control of the etching rate of the Bi 2 O 3 sheet template and the regrowth rate of Bi 2 S 3 crystallites via suitable sulfide precursor concentration during the hydrothermal reaction utilizes the formation of porous Bi 2 O 3 –Bi 2 S 3 sheets. Due to the presence of Bi 2 S 3 crystallites and porous structure in the Bi 2 O 3 –Bi 2 S 3 composites, the improved visible-light absorption ability and separation efficiency of photogenerated charge carriers are achieved. Furthermore, the as-synthesized Bi 2 O 3 –Bi 2 S 3 composite sheets obtained from vulcanization with a 0.01M Na 2 S precursor display highly enhanced photocatalytic degradation toward methyl orange (MO) dyes compared with the pristine Bi 2 O 3 and Bi 2 S 3 . The porous Bi 2 O 3 –Bi 2 S 3 sheet system shows high surface active sites, fast transfer, high-efficiency separation of photoinduced charge carriers, and enhanced redox capacity concerning their constituent counterparts. This study affords a promising approach to constructing Bi 2 O 3 -based Z-scheme composites with a suitable microstructure and Bi 2 O 3 /Bi 2 S 3 phase ratio for photoactive device applications.