In-situ growing Ni2P on CdS@g-C3N4 composites for highly efficient synergistically photocatalytic H2 evolution and antibiotic degradation

Abstract

Achieving simultaneous photocatalytic H2 evolution and antibiotic degradation is ideal but challenging. Herein, IS-Ni2P/CdS/CN ternary composites was elaborately constructed by electrostatic self-assembly followed by in-situ growth of Ni2P method. The IS-Ni2P/CdS/CN exhibit extremely high H2 yield and achieve synergistic degradation of multiple antibiotic contaminants (323 μmol g−1h−1 for H2 yield and 72 % for tetracycline hydrochloride synergistic degradation). Interestingly, for the synergistic mechanism, it is found that antibiotic molecules can serve as electron donors to promote the separation of carriers, thus remarkably improving H2 yield. More notably, the electron-donating capacity of antibiotic molecules dictates the synergistic efficiency, that is, the stronger the electron-donating capacity of antibiotic molecules, the more favorable it is for enhancing synergistic efficiency. Besides, experimental and DFT calculation demonstrate that the exceptional photocatalytic activity of IS-Ni2P/CdS/CN is ascribed to the combined effect of the induced internal electric field, and the improved interfacial contact by the in-situ grown Ni2P cocatalyst, thus substantially accelerating carriers transport. Our work provides an idea for simultaneous photocatalytic H2 evolution and pollutants degradation.