One-step preparation of hierarchical porous graphitic carbon nitride photocatalyst for wastewater treatment under real sunlight

Photocatalysis is a green and efficient way to handle antibiotic wastewater. However, most of the photocatalysts cannot be applied in real environments, which seriously hinders the development of photocatalysis in practical applications. In this study, we present an environmentally friendly one-step approach for fabricating g-C3N4 with hierarchical architecture by utilizing gas-phase template NH4Cl. The effects of various precursors, preparation methods, and additions of blowing agents on the structure and properties of g-C3N4 have been systematically investigated. Notably, g-C3N4 with hierarchical architecture (BSCN-3) demonstrated superior photocatalytic performance for Rhodamine B (RhB, 96.2 %, 20 min) and sulfamethoxazole (SMX, 80 %, 1 h) in comparison to both bulk g-C3N4 (BCN) and g-C3N4 nanosheets (SCN). This superior performance can be attributed to the exceptional properties of the hierarchical architecture, including its large specific surface area and enhanced capability for separating photogenerated carriers. Surprisingly, BSCN-3 exhibited remarkable performance in the degradation of dyes and antibiotics under real sunlight conditions (RhB, 95 %, 30 min, 65 mW cm−2). In addition, BSCN-3 exhibits excellent stability, with properties remaining unchanged over five consecutive cycles of degradation. This work presents a highly effective method for creating novel structured g-C3N4, which enables photocatalytic degradation of antibiotics in real environments, and greatly promotes the development of g-C3N4 for practical water treatment. [Display omitted]