利用Ni(OH) x 助催化剂修饰提高g-C 3 N 4 纳米片/WO 3 纳米棒Z型纳米体系的可见光产氢活性的研究
摘要
Abstract Novel WO 3 /g-C 3 N 4 /Ni(OH) x hybrids have been successfully synthesized by a two-step strategy of high temperature calcination and in situ photodeposition. Their photocatalytic performance was investigated using TEOA as a hole scavenger under visible light irradiation. The loading of WO 3 and Ni(OH) x cocatalysts boosted the photocatalytic H 2 evolution efficiency of g-C 3 N 4 . WO 3 /g-C 3 N 4 /Ni(OH) x with 20 wt%defective WO 3 and 4.8 wt%Ni(OH) x showed the highest hydrogen production rate of 576 μmol/(g–h), which was 5.7, 10.8 and 230 times higher than those of g-C 3 N 4 /4.8 wt%Ni(OH) x , 20 wt%WO 3 /C 3 N 4 and g-C 3 N 4 photocatalysts, respectively. The remarkably enhanced H 2 evolution performance was ascribed to the combination effects of the Z-scheme heterojunction (WO 3 /g-C 3 N 4 ) and loaded cocatalysts (Ni(OH) x ), which effectively inhibited the recombination of the photoexcited electron-hole pairs of g-C 3 N 4 and improved both H 2 evolution and TEOA oxidation kinetics. The electron spin resonance spectra of • O 2 − and • OH radicals provided evidence for the Z-scheme charge separation mechanism. The loading of easily available Ni(OH) x cocatalysts on the Z-scheme WO 3 /g-C 3 N 4 nanocomposites provided insights into constructing a robust multiple-heterojunction material for photocatalytic applications.