Enhanced photocatalytic activity over g-C3N4/(BiO)2(OH)xCl2−x Z-scheme heterojunction

Abstract

Photocatalytic degradation has been regarded as a promising method for environmental remediation. In this work, layered g-C3N4/(BiO)2(OH)xCl2−x (NBHC) heterojunction composites were synthesized by a hydrothermal method. The two-dimensional (2D)/2D porous layered Z-scheme heterojunction leaded to the suppressed recombination and the efficient separation of photogenerated electron-hole pairs. Meanwhile, NBHC composites exhibited a high specific surface area and rich mesopores for more reactive active sites. Thus, NBHC had an excellent photocatalytic degradation performance of pollutant trypan blue (TB). Furthermore, we found that the active species of superoxide radical (O2−) played a more important role, while hydroxyl radical (OH) contributed to a lesser extent in photocatalytic degradation of TB based on the active species capture experiment and electron spin resonance (ESR) spectra. A Z-scheme photocatalytic mechanism was proposed to understand the photodegradation of TB. This study may provide a new horizon for constructing novel Z-scheme heterostructure photocatalysts with an excellent performance.