Abstract
Constructing multi-heterojunction photocatalysts with multi-sources for carrier generation and with multi-channels for carrier transmission is one of the effective methods for enhancing the photocatalytic activity. Here, a novel TiO2/g-C3N4/Ag-AgBr (TCNAAB) multi-heterojunction photocatalyst was successfully constructed by depositing Ag-AgBr nanoparticles onto 3D spherical TiO2/g-C3N4. With the optimal ratio of TiO2, g-C3N4 and Ag-AgBr, the TCNAAB-50 composite had the highest H2 evolution activity and generated 940.5 μmol g?1 of H2, which was 8.24 times and 2.72 times higher than that generated by single TiO2 and binary TiO2/g-C3N4, respectively. Meanwhile, TCNAAB-50 also exhibited the highest photocatalytic activity toward methyl orange (MO) with the degradation efficiency of 77.6% under LED light. The enhanced photocatalytic performance is attributed to the multi-sources for carrier generation and the multi-channels for carrier transmission of the constructed multi-heterojunction, which help to effectively enhance the light absorption efficiency and the carrier separation and transmission. Based upon PL spectra, photoelectrochemical properties, radical quenching experiments and electron spin resonance spectra, a novel double Z-scheme heterojunction bridged by silver was proposed. The design of high-efficiency multi-heterojunction with multi-carrier excitation sources and multi-carrier transmission channels can be employed in improving the photocatalytic activity of single or binary component photocatalysts.
NSTL
Elsevier