Facile low-temperature co-precipitation method to synthesize hierarchical network-like g-C₃N₄/SnIn₄S₈ with superior photocatalytic performance

Hierarchical network-like graphitic carbon nitride/SnIn₄S₈ (g-C₃N₄/SnIn₄S₈) composites were prepared through a facile low-temperature co-precipitation method. The g-C₃N₄/SnIn₄S₈ composite showed enhanced visible-light absorption. The band gap energies of g-C₃N₄, pure SnIn₄S₈, and 15 % g-C₃N₄/SnIn₄S₈ are 2.58, 1.8, and 1.68 eV, respectively. The photocurrent and photocatalytic activity of the g-C₃N₄/SnIn₄S₈ composites firstly increased and then decreased with increasing g-C₃N₄ content, and it was found that the optimal 15 % g-C₃N₄/SnIn₄S₈ exhibited the highest photocurrent intensity and best photocatalytic performance with complete degradation of MO within 80 min under visible-light irradiation, which is much higher than that of pure SnIn₄S₈. The effect of main reactive species on the MO degradation follows the order of h⁺ > ^•O₂ ⁻ > ^•OH, and the possible degradation mechanism was proposed. Moreover, 15 % g-C₃N₄/SnIn₄S₈ exhibits excellent reusability and stability without an obvious decrease of photocatalytic activity after four consecutive photocatalytic degradation–regeneration cycles.