Fabrication of novel ternary heterojunctions of Pd/g-C3N4/Bi2MoO6 hollow microspheres for enhanced visible-light photocatalytic performance toward organic pollutant degradation

Abstract

To improve the photocatalytic performance of Bi2MoO6, novel ternary heterojunctions of Pd/g-C3N4/Bi2MoO6 (Pd/CN/BMO) hollow microspheres were fabricated through g-C3N4 coupling via solvothermal precipitation-calcination and metallic Pd deposition by photoreduction method. The optimal ternary 2Pd/10CN/BMO photocatalyst exhibited the highest photocatalytic efficiency towards Rhodamine B (RhB) degradation with a degradation rate of 97% under 40 min visible light irradiation, 77%, 61% and 18% higher than that of the single BMO (20%), binary 2Pd/10CN (61%) and 10CN/BMO (79%), respectively. The enhanced photocatalytic performance was mainly ascribed to the synergetic effect of heterojunction structures between g-C3N4 and Bi2MoO6 and the surface plasmon resonance (SPR) effect of Pd doping, resulting in the better optical absorption ability and lower combination rate of photogenerated charge carriers. Additionally, the 2Pd/10CN/BMO composite presented excellent photo-stability in recycling experiments. The trapping experiments demonstrated that the O2−, h+ and OH were separately the dominant, minor and the least important reactive species toward RhB degradation.