title: Enhanced visible-light photocatalytic activity of active Al₂O₃/g-C₃N₄ heterojunctions synthesized via surface hydroxyl modification.
abstract: Novel Al2O3/g-C3N4 heterojunction photocatalysts were fabricated through ultrasonic dispersion method. Al2O3, obtained via solution combustion, contained amorphous ingredient with lots of defect sites and was used as active component for transferring photo-induced electrons of g-C3N4. G-C3N4 was grafted surface hydroxyl groups in the presence of ammonia aqueous solution to combine with Al2O3 possessing positive charges via hydrogen bond. The XRD, SEM, element map, TEM, HRTEM, FT-IR, and XPS results indicate that these synthesized materials are two-phase hybrids of Al2O3 and g-C3N4 with interaction. The photocatalytic results for the degradation of rhodamine B (RhB) indicate that the most active heterojunction proportion is 60wt.% g-C3N4:40wt.% Al2O3, the visible light photocatalytic activity of which is 3.8 times that of a mechanical mixture. The enhanced performance is attributed to the high separation efficiency of photo-induced electrons from the LUMO of g-C3N4 injected into the defect sites of Al2O3, which is verified by photoluminescence spectroscopy (PL) and surface photovoltage (SPV) measurements. The electron paramagnetic resonance (EPR) signals and radical scavengers trapping experiments reveal holes (h(+)) and superoxide anion radical (O2(-)) are the main active species responsible for the degradation of RhB.
authors.affiliation: College of Science, Hebei University of Science and Technology, Shijiazhuang 050018, China. Electronic address: lifatang@126.com.
authors.forename: Fa-Tang
authors.initials: FT
authors.lastname: Li
authors.affiliation: College of Science, Hebei University of Science and Technology, Shijiazhuang 050018, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: College of Science, Hebei University of Science and Technology, Shijiazhuang 050018, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Wang
authors.affiliation: College of Science, Hebei University of Science and Technology, Shijiazhuang 050018, China.
authors.forename: Xiao-Jing
authors.initials: XJ
authors.lastname: Wang
authors.affiliation: College of Science, Hebei University of Science and Technology, Shijiazhuang 050018, China.
authors.forename: Ying-Juan
authors.initials: YJ
authors.lastname: Hao
authors.affiliation: College of Science, Hebei University of Science and Technology, Shijiazhuang 050018, China.
authors.forename: Rui-Hong
authors.initials: RH
authors.lastname: Liu
authors.affiliation: College of Chemical and Pharmaceutical Engineering, Hebei University of Science and Technology, Shijiazhuang 050018, China.
authors.forename: Dishun
authors.initials: D
authors.lastname: Zhao
mesh_terms: D000536:Aluminum Hydroxide / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry; D008956:Models, Chemical; D009570:Nitriles / Q000737:chemistry*; D055668:Photochemical Processes; D012235:Rhodamines / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000737:chemistry
chemical_list: D009570:Nitriles; D012235:Rhodamines; D014874:Water Pollutants, Chemical; D017665:Hydroxyl Radical; C011206:cyanogen; D000536:Aluminum Hydroxide; C029773:rhodamine B
keywords: Al(2)O(3); Heterojunction; Surface hydroxyl modification; Visible-light photocatalysis; g-C(3)N(4)