Construction of metal oxide decorated g-C3N4 materials with enhanced photocatalytic performance under visible light irradiation

Herein we report the synthesis and photocatalytic evaluation of heterostructure WO3/g-C3N4 (WMCN) and CeO2/g-C3N4 (CMCN) materials for RhB degradation and photoelectrochemical studies. These materials were synthesized by varying the dosages of WO3 and CeO2 on g-C3N4 individually and were characterized with state-of-the-art techniques like XRD, BET surface area, FT-IR, UV-Vis DRS, TGA, SEM, TEM and XPS. A collection of combined structural and morphological studies manifested the formation of bare g-C3N4, WO3, CeO2, WO3/g-C3N4 and CeO2/g-C3N4 materials. From the degradation results, we found that the material with 10 wt% WO3 and 15 wt% CeO2 content on g-C3N4 showed the highest visible light activity. The first order rate constant for the photodegradation performance of WMCN10 and CMCN15 is found to be 5.5 and 2.5 times, respectively, greater than that of g-C3N4. Photoelectrochemical studies were also carried out on the above materials. Interestingly, the photocurrent density of WMCN10 photoanode achieved 1.45cm-2 at 1.23 V (vs.) RHE and this is much larger than all the prepared materials. This enhanced photoactivity of WMCN10 is mainly due to the cooperative synergy of WO3 with g-C3N4, which enhanced the visible light absorption and suppresses the electron-hole recombination.Graphical Abstract Synopsis The WMCN materials exhibited superior photocatalytic performance than CMCN and bare g-C3N4 materials due to the existence of synergism between WO3 and g-C3N4. which enhanced the visible light absorption and suppresses the electron-hole recombination.