α-NiS/g-C3N4 Nanocomposites for Photocatalytic Hydrogen Evolution and Degradation of Tetracycline Hydrochloride

& alpha;-NiS/g-C3N4 nanocomposites were synthesized and used for photocatalytic hydrogen (H-2) evolution and tetracycline hydrochloride (TC) degradation. The fabricated nanocomposites were characterized by XRD, XPS, SEM, TEM, UV-vis DRS, TRPL, and PEC measurements. Photocatalytic studies show that the hydrogen generation rate of the 15%-& alpha;-NiS/g-C3N4 nanocomposite reaches 4025 & mu;mol & BULL;g(-1)& BULL;h(-1) and TC degradation rate 64.6% within 120 min, both of which are higher than that of g-C3N4. The enhanced performance of the nanocomposite is attributed to the formation of a heterojunction between & alpha;-NiS and g-C3N4 that enhances visible light absorption, promotes the separation and transfer of charges, and inhibits the recombination of carriers. The photocatalytic mechanism of the & alpha;-NiS/g-C3N4 heterojunction nanocomposite is discussed in terms of relevant energy levels and charge transfer processes.