Enhanced visible‐light‐driven photocatalytic application for water purification and hydrogen evolution by large‐sized nanofilm‐constructed hierarchical porous g‐C3N4/SiO2

Abstract

Abstract The large‐sized nanofilm‐constructed hierarchical porous SiO2 (LNCHPS) is successfully prepared by the dual templating approach and subsequently used as the support for g‐C3N4. A series of characterization techniques are conducted to evaluate the structure and property of the as‐prepared materials. The LNCHPS possesses two sets of explicated successive pass‐through macropores (0.5–1.0 µm) with large specific surface area. In addition, the macropore wall is constructed by uniform mesoporous nanofilms with the thickness ranging from 35 to 50 nm. Then, the photocatalytic property is investigated by degradations towards Rhodamine B (RhB) under simulated sunlight, in which experiments have been performed through controlling the g‐C3N4 loading contents, solution pH values, and photocatalyst dosages. The apparent rate constant of g‐C3N4/LNCHPS could reach 0.03 min−1 under optimum conditions, showing 6.0 times that of the bulk g‐C3N4. In addition, g‐C3N4/LNCHPS also exhibits significantly enhanced performance in H2 evolution (39.9 µmol h−1) compared to that of the bulk g‐C3N4. High light absorption and utilization, enhanced adsorption capability and quick electron hole separation can render this fine structure excellent photocatalytic performance. Our work enables a facile route for large‐scale preparation of g‐C3N4/LNCHPS for addressing the wastewater treatment and hydrogen energy production simultaneously.

Keywords

• degradation of organic pollutant
• graphitic carbon nitride
• hierarchical porous silica
• hydrogen evolution
• photocatalysis