Enhancement of Photocatalytic Activity under Visible Light Irradiation via the AgI@TCNQ Core-Shell Structure

Preparation of g-C3N4/TCNQ Composite and Photocatalytic Degradation of Pefloxacin

g-C₃N₄ and g-C₃N₄/TCNQ composites with different doping levels were prepared using the copolymerization thermal method with melamine as a precursor. XRD, FT-IR, SEM, TEM, DRS, PL, and I-T characterized them. The composites were successfully prepared in this study. The photocatalytic degradation of pefloxacin (PEF), enrofloxacin (ciprofloxacin), and ciprofloxacin (ciprofloxacin) under visible light (λ > 550 nm) showed that the composite material had the best degradation effect on PEF. When TCNQ doping is 20 mg and catalyst dosage is 50 mg, the catalytic effect is the best, and the degradation rate reaches 91.6%, k = 0.0111 min^-1, which is four times that of g-C₃N₄. Repeated experiments found that the cyclic stability of the g-C₃N₄/TCNQ composite was good. The XRD images were almost unchanged after five reactions. The radical capture experiments revealed that ·O^2- was the main active species in the g-C₃N₄/TCNQ catalytic system, and h⁺ also played a role in PEF degradation. And the possible mechanism for PEF degradation was speculated.

Ce and Er Co-doped TiO2 for rapid bacteria- killing using visible light

Bacterial infection and related diseases are threatening the health of human beings. Photocatalytic disinfection as a simple and low-cost disinfection strategy is attracting more and more attention. In this work, TiO2 nanoparticles (NPs) were modified by co-doping of Ce and Er using the sol-gel method, which endowed TiO2 NPs with enhanced visible light photocatalytic performance but not pure ultraviolet photocatalytic properties compared the untreated TiO2. Our results disclosed that as the doping content of Er increased, the photocatalytic activity of modified TiO2 NPs initially increased and subsequently decreased. The same trend occurred for Ce doping. When the doping dose of Er and Ce is 0.5 mol% and 0.2 mol%, the 0.5Ce0.2Ti-O calcined at 800 °C presented the best antibacterial properties, with the antibacterial efficiency of 91.23% and 92.8% for Staphylococcus aureus and Escherichia coli, respectively. The existence of Er ions is thought to successfully turn the near-infrared radiation into visible region, which is easier to be absorbed by TiO2 NPs. Meanwhile, the addition of Ce ions can effectively extend spectral response range and inhibit the recombination of electrons and holes, enhancing the photocatalytic disinfection activity of co-doped TiO2.