Synthesis of α-Fe(2)O(3)/Bi(2)WO(6) layered heterojunctions by in situ growth strategy with enhanced visible-light photocatalytic activity

Layered heterojunction structure with larger interface region for electron migration has attracted much attention in recent years. In this work, layered α-Fe(2)O(3)/Bi(2)WO(6) heterojunctions with strong interlayer interaction were successfully synthesized through a facile in situ growth method. The strong interaction between α-Fe(2)O(3) and Bi(2)WO(6) had resulted in excellent photoelectrochemical performance. It was found that such structure promoted the interfacial photogenerated charges separation according to EIS and Tafel analysis, except for the expansion of visible-light absorption range. PL and TRPL characterizations further demonstrated that the recombination ratio of photoexcited electron-hole pairs was greatly reduced. The toluene photocatalytic degradation tests had showed that α-Fe(2)O(3)/Bi(2)WO(6) composites exhibited much well activity under visible-light irradiation. Especially, 4%-Fe(2)O(3)/Bi(2)WO(6) sample displayed the highest photocatalytic activity, which was around 3 and 4 times higher than that of pure Bi(2)WO(6) and α-Fe(2)O(3). Based on ESR results and free radical trapping experiments, hydroxyl radicals (·OH) and holes (h(+)) were regarded as the main active species. The establishment of Fe(2)O(3)/Bi(2)WO(6) with layered heterojunctions could provide new insights into the construction of novel photocatalysts.