Abstract
Layered heterojunction structure with larger interface region for electron migration has attracted much attention in recent years. In this work, layered α-Fe2O3/Bi2WO6 heterojunctions with strong interlayer interaction were successfully synthesized through a facile in situ growth method. The strong interaction between α-Fe2O3 and Bi2WO6 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-Fe2O3/Bi2WO6 composites exhibited much well activity under visible-light irradiation. Especially, 4%-Fe2O3/Bi2WO6 sample displayed the highest photocatalytic activity, which was around 3 and 4 times higher than that of pure Bi2WO6 and α-Fe2O3. 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 Fe2O3/Bi2WO6 with layered heterojunctions could provide new insights into the construction of novel photocatalysts.
Highlights
Tafel analysis, except for the expansion of visible-light absorption range
The intensity of the diffraction peaks of α-Fe2O3/Bi2WO6 composites was stronger than that of pure Bi2WO6, which could be ascribed to the growth of crystals during the www.nature.com/scientificreports hydrothermal process
It was noteworthy that no peaks of α-Fe2O3 were observed for α-Fe2O3/Bi2WO6 composite photocatalysts, which may be ascribed to the high dispersion and low content of α-Fe2O329
Summary
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. Many kinds of photocatalysts have been extensively investigated, such as TiO27–9, ZnO10,11, SnO212, SrTiO313 and so on These semiconductors still have some common shortcomings, such as narrow light absorption range and high recombination ratio of photogenerated charges[14]. Layered heterojunction photocatalyst possesses larger interfacial area compared to line contact and point contact heterojunction photocatalysts, which benefits the transfer of photogenerated electron-hole pairs[23] By taking this advantage into consideration, many photocatalysts with layered heterostructure have been fabricated, such as SnS2/g-C3N423, g-C3N4/Bi2WO624, g-C3N4/Bi20TiO3225, α-Fe2O3/graphene[26] and so on. Motivated by the above work, Bi2WO6 coupled with α-Fe2O3 (a low-price and narrow band gap semiconductor) nanosheets as layered heterojunction photocatalyst may exhibit significantly enhanced photoinduced interfacial charge transfer rate, which could effectively promote the photocatalytic activity. The main purpose of our work was to shed new light on the synthesis of layered heterojunctions and reveal the role of such structure in photocatalytic process
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
