Synergy effect in the photocatalytic degradation of methylene blue on a suspended mixture of TiO2 and N-containing carbons

Eco-Friendly Heterogeneous Photocatalysis on Biochar-Based Materials Under Solar Irradiation

“…The synthesis of Au-TiO 2 /AC photocatalysts was performed in a two-step procedure [6]. Au was firstly deposited at basic pH on a commercial P25 TiO 2 from Evonik by the method described elsewhere [6] and then Au-TiO 2 /C binary hybrid materials were prepared by a slurry method [4][5][6]. Activated carbons (AC) supports for the H 2 photoproduction were prepared from sawdust of Tabebuia Pentaphyla wood by changing experimental conditions and the activation temperature in order to introduce different physicochemical properties [6], mainly, texture and in the nature and density of the functional groups on carbon surface.…”

“…The initial carbons are referred as B (commercial BAX-1500) and C (home-made carbon) and their S-doped counterparts as B-S and C-S. S-doped carbons were obtained exposing carbons to H 2 S flow by 3 h at 800°C. For the case of N-containing carbons [5] waste plum stones (P) was the starting material and carbons were prepared by pyrolysis or physical activation under steam. The material was subjected to steam activation, to nitrogen modification by ammoxidation (NH 3 /air mixture), with or without following steam activation, and by nitrogenation (NO).…”

“…These works have showed that C-based materials induce enhancements in the photocatalytic activity in different processes related with the environmental remediation of polluted water (phenol, halophenols, herbicides, dyes, azo-dyes, among others) and air (toluene, 2-propanol among others) and for the solar energy conversion by visible light-induced chemical transformation such as hydrogen photoproduction under solar irradiation which is a clear example of catalysis for energy storage by using carbon-supported materials. In this sense, the main objective of the present work is to present a revision of previous kinetic results from our group [4][5][6][7] to show the potential of Carbon-based materials in the photodegradation of methylene blue and in the photoproduction of hydrogen with a special emphasis in the use artificial of solar irradiation. Also, new correlations between the photocatalytic activity with the sulfur-or nitrogen composition and with the textural properties of biochar-based materials are presented in this work.…”

“…However, the large-scale implementation of photocatalytic processes in environmental remediation is yet hindered by technological and economical drawbacks (mainly low semiconductor activity under visible light, high recombination rate of photogenerated electron-hole pairs, and recovery and reutilization issues) [2]. Recent developments from our group [4][5][6][7] and several works from other groups [8][9][10][11][12][13][14][15][16] pay special attention to different potential application of carbon-based materials. The enhanced photocatalytic performance of carbon/TiO 2 composites has been mainly attributed to the porosity of the carbon support, and/or strong interfacial electronic effects [4][5][6][7][8].…”

“…Recent developments from our group [4][5][6][7] and several works from other groups [8][9][10][11][12][13][14][15][16] pay special attention to different potential application of carbon-based materials. The enhanced photocatalytic performance of carbon/TiO 2 composites has been mainly attributed to the porosity of the carbon support, and/or strong interfacial electronic effects [4][5][6][7][8]. More recently, our previous studies have demonstrated the photochemical intrinsically reactivity of activated carbons under UV irradiation and their ability to generate O-radical species upon UV irradiation [9,10].…”