A visible light-response La-doped MnIn2S4 with enhanced performance for removing tetracycline hydrochloride and triphenylmethane dyes in wastewater

Impurity element doping is widely considered to be one of most efficient methods to adjust the electronics construction and the photocatalyst photo-generated separation of charge. In this work, a series of novel flower-like La-doped MnIn2S4 photocatalysts (x wt% La-doped MnIn2S4, x = 0, 5, 10, 20, 30) were prepared by hydrothermal synthesis and adopted various analysis techniques. The results showed that La-doped MnIn2S4 manifested significant photocatalytic performance for the photodegradation of tetracycline hydrochloride (TCH) and triphenylmethane dyes. The removal efficiency of malachite green (MG) and TCH reach 98.1% and 97.9% in 60 min, respectively. In the presence of visible light, the apparent reaction rate of 10 wt% La-doped MnIn2S4 (10 L-MIS) obtained 0.1237 min−1, approximately 13 times that of MIS. The mechanism of photocatalytic degradation has been established that •O2− is the primary active species in the degradation process. At the same time, by researching the antibacterial activity of La-doped MnIn2S4, both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus are resistant to the antibacterial capabilities of the La-doped MnIn2S4 nanocomposite material. The Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus were selected to study the antibacterial activity of La-doped MnIn2S4. The antibacterial results reflect that the synthesized La-doped MnIn2S4 nanocomposite material has excellent antibacterial properties. For the sake of verifying the low toxicity of La-doped MnIn2S4, HCT-116 and HEB were used to investigate the cytotoxicity of La-doped MnIn2S4. Due to the synergistic effect of increased visible-light absorption ability and favorable photogenerated charge carrier separation, the photoactivity of doped MnIn2S4 was significantly increased. The developed La-doped MnIn2S4 nanocomposite materials present high-efficiency photocatalytic activity and have broad application prospects in wastewater and pollutant treatment.