Design of 2D–2D NiO/g-C₃N₄ heterojunction photocatalysts for degradation of an emerging pollutant

Abstract: The release of a large number of antibiotics to the environment has created a shade of sorrow in the scientific community. Herein, two-dimensional (2D)–2D NiO/g-C₃N₄ photocatalysts were synthesized and applied for the photodegradation of tetracycline hydrochloride antibiotic. This 2D–2D heterojunction catalyst showed effective photoactivity due to the large contact area promoting the interfacial charge transfer rate. The improved photoactivities were attributed to the formation of complete face-to-face heterojunctional channels between two nanosheets of NiO and g-C₃N₄, which play a major contribution in the transfer of excited charges in the nanocomposite. Besides, the formation of Z-type heterojunction protects the high redox ability of two semiconductors. The photocatalytic activities were high at neutral pH values and decreased when pH values were changed. The photocatalytic activities were also checked in the presence of certain anions such as sulfate, chloride, carbonate), nitrate, and phosphate. Finally, a possible schematic mechanism was planned for charge separation in the nanocomposite. Graphic abstract: 2D-2D NiO/g-C₃N₄ photocatalysts demonstrate high photocatalytic activity for degradation of tetracycline hydrochloride antibiotic due to the large contact area and Z-scheme heterojunction promoting the interfacial charge transfer rate.[Figure not available: see fulltext.].