Chengyang Wang

Antimicrobial resistance (AMR) has disturbed global public health for many years. Reactive oxygen species (ROS) generation by photocatalysis was considered as an effective substance which can directly destroy cell structures and DNA of bacterial. In this work, Ag cluster decorated BiO _{2‐ x} (Ag‐BiO _{2‐ x} ) Ohmic‐junction with strong built‐in electric field was fabricated by photo‐deposition strategy for efficient photocatalytic sterilization. The interfacial reaction‐generated electric field in an Ag‐BiO _{2‐ x} Ohmic‐junction facilitates the transport and separation of photoelectron from BiO _{2‐ x} to Ag. The local surface plasmon resonance (LSPR) effect of Ag clusters can boost the composite’s light absorption while preventing photogenerated carriers from recombining. Simultaneously, Ag clusters can act as a cocatalyst, with an optimal oxygen‐adsorption energy, promoting highly efficient molecular oxygen activation. As we expected, Ag‐BiO _{2‐ x} Ohmic‐junction displayed enhanced E. coli inactivation activity with 2 h under visible light irradiation. The EPR measurement and DFT calculation confirmed that the Ag clusters worked as ROS generation sites and provoked the generation of · O ₂ ⁻ and ·OH. This study provides an atomic insight on design Ohmic‐junction photocatalyst for photocatalytic antibacterial.

Antibiotic-based wastewaters seriously endanger human health and damage the ecological environment, and photocatalytic degradation is a desirable strategy for eliminating these contaminants in water. Therefore, developing a proper catalyst for the photodegradation of antibiotics, including ciprofloxacin (CIP), is of great importance. In this study, novel Ag₂S/Zn²⁺-decorated graphitic carbon nitride (AZCN for short) type-II heterojunctions are constructed through a precipitation–calcination procedure. The high porosity with a specific surface area of 133.5 m² g⁻¹, as well as the positive synergy between Ag₂S- and Zn²⁺-decorated graphitic carbon nitride (abbreviated as ZCN), enhance incident light harvesting, increase the adsorption capacity for reactant molecules, favor mass transfer and promote the separation and transport of photoinduced carriers, therefore improving the degradation efficiency of CIP. Specifically, the degradation efficiency of CIP (50 mL, 10 mg L⁻¹) over 2.5% AZCN (10 mg) is 18.1%, 43.1% and 55.7% within 60 min of irradiation using near-infrared light, visible light and simulated solar light, respectively. Moreover, it displays satisfactory recycling stability and excellent universality. This research not only develops a promising heterojunction photocatalyst but also offers some valuable insights in water remediation.