The role of the surface acidic/basic centers and redox sites on TiO2 in the photocatalytic CO2 reduction

Targeted H2O activation to manipulate the selective photocatalytic reduction of CO2to CH3OH over carbon nitride-supported cobalt sulfide

“…[31][32][33][34][35][36] However, it is noteworthy that the content of protons generated often exhibits a positive correlation with the concentration of strongly oxidizing species generated owing to the sluggish reaction kinetics in the photocatalytic H 2 O oxidation process. 4,15,37,38 Thus, based on the above-mentioned considerations, solving this dilemma is highly required for achieving the selective photocatalytic reduction of CO 2 to CH 3 OH with high activity but a huge challenge. However, few studies have focused on the effect of the oxidative free radicals generated by H 2 O activation on the selectivity of the CO 2 reduction products to date.…”

Insights into Chlorobenzene Catalytic Oxidation over Noble Metal Loading {001}-TiO2: The Role of NaBH4 and Subnanometer Ru Undergoing Stable Ru0↔Ru4+ Circulation

“…Moreover, negative bands of hydroxyl species for prepared catalysts at approximately 3670 cm −1 were also observed (Figure S8), which were assigned to the consumption of Ti-O(H)-Ti species (Brønsted acid sites) and the hydroxyl group attached to the five-coordinatively unsaturated Ti atoms (Ti-OH) on the surface of {001}-TiO 2 (Brønsted basic sites). 37,56,57 It's apparent that adding NaBH 4 enhanced the generation of the hydroxyl group on {001}-TiO 2 , endowing Ru/{001}-TiO 2 and Pd/{001}-TiO 2 with a certain amount of hydroxyl species, which could break the C-Cl of CB into phenolates and then into quinone or ketone species. 9 To further explore the CB degradation process, the quantitative analysis of multiple volatile organic byproducts in the off-gas was conducted by a GC-FID/MS system.…”

Improved Methane Production by Photocatalytic CO2 Conversion over Ag/In2O3/TiO2 Heterojunctions

“…The suspension was then treated in an ultrasonic bath for 1 h, and the water was eliminated by evaporation at 100 • C. Afterward, the samples were ground in an agate mortar, calcined in air at 400 • C for 4 h with a temperature ramp of 10 • C/min, and finally ground again. This temperature was chosen in order to eliminate any possible organic impurity while avoiding the phase change of TiO 2 from anatase to rutile [8,39]. The catalysts were labeled as xIn 2 O 3 -c/TiO 2 , where x indicates the nominal In amount in wt.%.…”

“…According to ICP and XPS chemical analyses (see results in Table 1), the Ag surface fraction was 3.1 and 2.3 wt.% for Ag/1In 2 O 3 -c/TiO 2 and Ag/1In 2 O 3 -p/TiO 2 , respectively. Provided that silver was only decorating the TiO 2 surface, the higher Ag concentration in the c-series catalyst may have resulted from lower surface interaction with In 2 O 3 particles due to the higher crystallite size of the commercial In 2 O 3 sample [6,8,39].…”

“…However, TiO 2 presents some disadvantages which limit its efficiency; it is only active under UV light and the photogenerated electron-hole pairs recombine with a high rate. In the last few years, researchers have been developing different strategies of modification to enhance the photocatalytic performance of TiO 2 , such as the use of dopants, cocatalysts, heterojunctions, single active sites, and bandgap engineering [6][7][8][9][10][11][12][13][14]. Among them, the formation of heterojunctions shows great potential because of its versatility and its effectiveness in reducing the recombination of electron-hole pairs, thus improving the charge separation and enhancing photocatalytic performance [9,[15][16][17][18].…”