Self-assembly Cu₂O nanowire arrays on Cu mesh: A solid-state, highly-efficient, and stable photocatalyst for toluene...

Sunlight driven photocatalysis offers an effective and eco-friendly technology for volatile organic compounds (VOCs) removal. Three dimensional (3D) and oriented structure can facilitate efficient photon absorption and rapid diffusion of VOCs, which prevails over the powder-formed catalysts. Herein, free-standing and uniform p-type Cu₂O nanowire (NW) arrays were obtained through heat treatment of Cu(OH)₂ NWs, which were spontaneously grown from Cu mesh in air under room temperature for the first time. The as-prepared Cu₂O NWs show excellent degradation performance in decomposing 30 ppm toluene (99.9 % within 120 min) and high stability (no decline after ten recycles). The toluene degradation was also conducted under the natural sunlight, demonstrating complete removal from 12:00 am to 15:00 pm. During photocatalysis, toluene is attacked by the photogenerated holes (h⁺) and hydroxyl radicals (·OH), and finally oxidized to nontoxic small molecules. The photocatalytic removing toluene with Cu₂O NWs/Cu mesh has a promising application prospect owing to its low cost, high efficiency, stability, and convenient operation.