Multiple photocatalytic applications of non-precious Cu-loaded g-C3N4/hydrogenated black TiO2 nanofiber heterostructure

Abstract

TiO2-based semiconductors are widely utilized for photocatalytic H2 evolution and environmental remediation; however, there are limited studies on a single photocatalyst that exhibits high photocatalytic performance in multiple applications. Herein, a non-precious Cu-loaded g-C3N4/1D hydrogenated black TiO2 nanofiber (CuCNBTNF) heterostructure was fabricated and investigated for H2 evolution, gaseous organic pollutant removal, and aqueous dye pollutant removal under simulated solar or daylight fluorescent lamp irradiation. A CuCNBTNF sample with a CN-to-Cu/BTNF wt% of 5 (CuCNBTNF-5) showed the highest photocatalytic performance for H2 evolution (16.9 mmol g−1), gaseous ethylbenzene removal (63.2%), and aqueous rhodamine B removal (86.2%). In addition, the photocatalytic performance of CuCNBTNF-5 was much higher than those of the selected reference catalysts, which was ascribed to the synergistic interaction of Cu, g-C3N4, and black TiO2 nanofiber. The enhanced charge carrier separation efficiency was inferred from the photoluminescence emission spectra. The H2 evolution yield remained essentially constant after five cycles, indicating the long-term photostability of the photocatalyst. A type II heterojunction mechanism of CuCNBTNF for H2 evolution and pollutant degradation was proposed on the basis of hydroxyl radical measurements and analysis of band energy structure. Therefore, the CuCNBTNF photocatalyst is a promising candidate for multiple photocatalytic applications.