• 文献标题:   N/S-doped graphene derivatives and TiO2 for catalytic ozonation and photocatalysis of water pollutants
  • 文献类型:   Article
  • 作  者:   PEDROSA M, PASTRANAMARTINEZ LM, PEREIRA MFR, FARIA JL, FIGUEIREDO JL, SILVA AMT
  • 作者关键词:   graphene, nitrogen sulphur doping, tio2, catalytic ozonation, photocatalysi, water treatment
  • 出版物名称:   CHEMICAL ENGINEERING JOURNAL
  • ISSN:   1385-8947 EI 1873-3212
  • 通讯作者地址:   Univ Porto
  • 被引频次:   25
  • DOI:   10.1016/j.cej.2018.04.214
  • 出版年:   2018

▎ 摘  要

Graphene oxide (GO) was synthesized by two methods (Hummers and Brodie), N and S-doping of reduced graphene oxide (rGO) being achieved by thermal treatment. These materials were tested as ozonation catalysts, the N-doped (3.3 at.%) material prepared by Brodie's method accomplishing complete removal of oxalic acid, while this compound is refractory to non-catalytic ozonation. Titanium dioxide (TiO2) nanoparticles were then introduced as own catalytic phase and protection component to avoid the strong erosive effect of ozone over the carbon phase (GO, rGO, N-and S-doped rGO, obtained by both methods). Among the resulting set of eight TiO2-based composites, the highest catalytic activity in ozonation was obtained with the composite containing N-doped reduced graphene oxide derived from Hummers' method (rGOT-H-N, k(app)=9.87x10(-3) min(-1)). This was attributed to the high content of oxygen in the graphene oxide precursor, the oxygen surface groups acting as reactive sites for doping of N-functionalities and mediating the efficient and uniform assembly of TiO2 nanoparticles on graphene oxide sheets. The same composites, plus two prepared by simple mixing and sonication, were then tested in the photocatalytic degradation of diphenhydramine under near-UV/Vis radiation. Those with graphene oxide (GOT-H and GOT-B) exhibited the highest photocatalytic activity (k(app)=52.5x10-(3) and 51.3x10(-3) min(-1), respectively), ascribed to the largest blue shift of the band in the UV range and lowest photoluminescence intensity in the visible range. Thus, reduction of graphene oxide has a negative effect in the case of photocatalysis.