Full spectrum responsive In2.77S4/WS2 p-n heterojunction as an efficient photocatalyst for Cr(VI) reduction and tetracycline oxidation

In the present work, wrinkled n-type WS2 nanosheets were synthesized and then used to construct the In2.77S4/WS(2 )p-n heterojunction photocatalyst. Experimental results reveal that the as-prepared hybrids present excellent photocatalytic activity for Cr(VI) reduction and tetracycline oxidation under visible and infrared light irritation. The photocatalytic efficiency of the as-prepared catalysts is found to increase initially followed by the decrease with the more weight content of WS2. When WS(2 )is up to 4 wt%, the as-prepared photocatalysts exhibit the highest photocatalytic activity, and are capable of reducing 99.1% of Cr(VI) in 60 min and oxidizing 87.5% of tetracycline in 20 min, much higher than 86.6 and 40.0% of pure In2.77S4, respectively. This enhanced photocatalytic activity is attributed to the construction of In2.77S4/WS2 p-n heterojunction between p-In2.77S4 and n-WS2. The detailed clarification of photocatalytic mechanism is also elaborated in the paper.