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

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.