Synthesis of a hydrophilic α-sulfur/PDA composite as a metal-free photocatalyst with enhanced photocatalytic performance under visible light

The polydopamine (PDA) coating α-S hydrophilic composites (SD) were fabricated by a self-assembly process for enhanced α-S photocatalytic performance under visible light. The XRD patterns analysis indicated that we had successfully prepared the orthorhombic α-S. The SEM, FT-IR and TGA showed that PDA had been successfully coated on α-S. The photocatalytic ability was illustrated by the DRS and FL. Moreover, the measurement of the water contact angle of SD and the corresponding original α-S (SA) showed the hydrophilicity of α-S had been improved. The photocatalytic ability of SD and SA was evaluated by photocatalytic decomposition of Methylene blue (MB) solution. The MB elimination rate with SD in the photocatalytic process was 2.46 times as great as that with SA under visible light. The enhanced photocatalytic ability could be attributed to the improved hydrophilicty of α-S.