Synthesis of SnO2/yolk-shell LaFeO3 nanocomposites as efficient visible-light photocatalysts for 2,4-dichlorophenol degradation

Herein, yolk-shell LaFeO3 (YS-LFO) microsphere has been successfully prepared by a carbon microsphere (CMS) template-adsorption-calcination method. It was confirmed that the YS-LFO microspheres showed high visiblelight photoactivities for 2,4-dichlorophenol degradation as compared to bare LaFeO3 (LFO) nanoparticles, attributing to the unique yolk-shell structure and the increased surface area. The visible-light photocatalytic activities of YS-LFO microspheres could be further promoted by coupling with SnO2 (SO) nanoparticles. Based on the surface photovoltage spectra, photoelectrochemical measurements and other characterization, it was demonstrated that the coupled SO afforded a thermodynamically suitable platform for accepting the high-level energy electrons from LaFeO3 so as to enhance the charge separation. Compared with YS-LFO microspheres and LFO nanoparticles, the amount optimized (10SO/YS-LFO) nanocomposites displayed 1.6 and 4.7-time enhancement for 2,4-dichlorophenol degradation under visible-light irradiation, respectively. This efficient strategy of morphology controlling and photoelectron modulating could pave the approach to design high-ctivity visible-light driven photocatalysts.