• 文献标题:   Photocatalytic H-2 production and degradation of aqueous 2-chlorophenol over B/N-graphene-coated Cu-0/TiO2: A DFT, experimental and mechanistic investigation
  • 文献类型:   Article
  • 作  者:   OMBAKA LM, MCGETTRICK JD, OSEGHE EO, ALMADANAT O, BEST FRG, MSAGATI TAM, DAVIES ML, BREDOW T, BAHNEMANN DW
  • 作者关键词:   green energy, hydrogen production, metallic copper, photocatalysi, 2chlorophenol degradation
  • 出版物名称:   JOURNAL OF ENVIRONMENTAL MANAGEMENT
  • ISSN:   0301-4797 EI 1095-8630
  • 通讯作者地址:  
  • 被引频次:   4
  • DOI:   10.1016/j.jenvman.2022.114822 EA MAR 2022
  • 出版年:   2022

▎ 摘  要

Energy and environmental challenges are global concerns that scientists are interested in alleviating. It is on this premise that we prepared boron/nitrogen graphene-coated Cu0/TiO2 (B/N-graphene-coated Cu/TiO2) photocatalyst of varying B:N ratios with dual functionality of H2 production and 2-Chlorophenol (2-CP) degradation. In-situ coating of Cu0 with B/N-graphene is achieved via solvothermal synthesis and calcination under an inert atmosphere. All B/N-graphene-coated Cu/TiO2 exhibit higher photonic efficiencies (5.68%-7.06% at 300 < lambda < 400 nm) towards H2 production than bare TiO2 (0.25% at 300 < lambda < 400 nm). Varying the B:N ratio in graphene influences the efficiency of H2 generation. A B:N ratio of 0.08 yields the most active composite exhibiting a photonic efficiency of 7.06% towards H2 evolution and a degradation rate of 4.07 x 10-2 min-1 towards 2-chlorophenol (2-CP). Density functional theory (DFT) investigations determine that B-doping (p-type) enhances graphene stability on Cu0 while N-doping (n-type) increases the reduction potential of Cu0 relative to H+ reduction potential. X-ray photoelectron spectroscopy reveals that increasing the B:N ratio increases p-type BC2O while decreasing n-type pyridinic-N in graphene thus altering the interlayer electron density. Isotopic labelling experiments determine water reduction as the main mechanism by which H2 is produced over B/N-graphenecoated Cu/TiO2. The reactive species involved in the degradation of 2-CP are holes (h+), hydroxyl radical (OH center dot), and O2 center dot-, of which superoxide (O2 center dot-) plays the major role. This work displays B/N -graphene-coated Cu/ TiO2 as a potential photocatalyst for large-scale H2 production and 2-CP degradation.