One-pot synthesis of BiSCl–Bi6.88S8·64Cl3.36 nanorods for rhodamine B photodegradation in water

Abstract

In the domain of water treatment, photocatalytic degradation presents a compelling approach. However, the quest for photocatalysts that exhibit superior solar energy absorption and conversion remains a challenge. We explore rod-shaped bismuth-rich chalcohalide photocatalyst BiSCl–Bi6.88S8·64Cl3.36 by simple temperature control and demonstrate the proficiency in degrading organic pollution under visible light. BiSCl–Bi6.88S8.64Cl3.36 nanorods manifest a composition-tailored band gap, effectively spanning the visible spectrum. Remarkably, in the absence of cocatalysts and sacrificial agents, BiSCl–Bi6.88S8·64Cl3.36 exhibit exceptional photocatalytic degradation rate of 99.8%, which is comparable to that of BiSBr (98.6%). Moreover, the photodegradation rate of BiSCl–Bi6.88S8·64Cl3.36 (0.091 min−1) is higher than that of BiSBr (0.048 min−1). The rate position it among the most effective known photocatalysts, with the generation of superoxide anion radicals (•O2−) and photogenerated holes (h+) as the primary active species. Notably, the enhanced photocatalytic activity of BiSCl–Bi6.88S8·64Cl3.36 is attributed to the high number of Bi centers and the higher electronegativity, which induces a more polar crystal structure.