Wu, N.-L.N.-L.WuLee, M.-S.M.-S.LeePon, Z.-J.Z.-J.PonHsu, J.-Z.J.-Z.HsuNAE-LIH WU2020-01-062020-01-062004https://scholars.lib.ntu.edu.tw/handle/123456789/445670TiO2 photocatalysts were synthesized by a sol-gel process followed by calcination at 400 °C in Ar, air, N2, H2 (3% in N2) and vacuum (∼5×10-3 torr), respectively. Toward H2 production from a water/methanol (vol. ratio=1.4/1) solution, the catalysts exhibited activities in the order, according to calcination atmosphere, of Ar>air>N2>vacuum∼H2. The low activity resulting from either vacuum or H2 calcination was ascribed to a reduced coverage of surface hydroxyl and high bulk defect density, based on the X-ray photoelectron and UV-Vis spectroscopic analyses, while the high activity from Ar calcination is to enhanced visible-light excitation. © 2004 Elsevier B.V. All rights reserved.Calcination atmosphere; Hydrogen production; Methanol; Phototcatalysis; TiO2; X-ray photoelectron spectroscopy[SDGs]SDG6[SDGs]SDG7argon; hydrogen; hydroxyl group; methanol; nitrogen; titanium dioxide; water; air; article; atmosphere; catalyst; chemical procedures; controlled study; gel; light; photocatalysis; solid; surface property; synthesis; temperature; ultraviolet spectroscopy; vacuum; X ray photoelectron spectroscopyjournal article10.1016/j.jphotochem.2003.12.0092-s2.0-1342328629https://www.scopus.com/inward/record.uri?eid=2-s2.0-1342328629&doi=10.1016%2fj.jphotochem.2003.12.009&partnerID=40&md5=dcdf628550149a720884bb75713f828c