Photocatalytic conversion of glucose in aqueous suspensions of heteropolyacid–TiO₂ composites

Abstract

Commercial and home prepared TiO 2 samples were functionalized with a commercial Keggin heteropolyacid (HPA) H 3 PW 12 O 40 (PW 12 ) or with a hydrothermally home prepared K 7 PW 11 O 39 salt (PW 11 ).All the materials were characterized by specific surface area measurements (BET), XRD analyses, Raman, DRS along with SEM observations and they have been used for glucose photocatalytic conversion in an aqueous suspension. Different reaction extents and distribution of intermediate oxidation products were observed depending on the photocatalyst. Gluconic acid, arabinose, erythrose and formic acid were observed as oxidation products when bare TiO 2 or HPA/TiO 2 composite materials were used. Glucose isomerization to form fructose was also observed and in some runs traces of glucaric acid and glyceraldehyde were also found. The carbon mass balance was accomplished in the presence of the commercial Evonik P25 TiO 2 powder and the composites where TiO 2 was present, whereas the presence of the solvothermically prepared TiO 2 gave rise to a carbon unbalance, due to strong adsorption of the products on the photocatalyst surface. No reactivity was observed in the presence of PW 12 alone while PW 11 induced only isomerization of the glucose.

Synergistic Effects of Co-Doping on Photocatalytic Activity of Titanium Dioxide on Glucose Conversion to Value-Added Chemicals

“… 43 In addition, the glucose conversion with a short reaction time in this study was relatively high compared with the previous work using heteropolyacid-TiO 2 composites. 44 This suggested that the synergistic effect of the co-dopants on the photocatalysts has a significance. Time-course profiles of the products from the photocatalytic reactions are shown in Figure 8 .…”

“…In comparison, the product distribution was similar to the previous reports based on the oxidation pathway. 15 , 44 However, the difference on selectivity of the derived products was observed in the presence of the Cr–TiO 2 -supported photocatalyst. 14 In addition, the use of rutile TiO 2 -based photocatalysts also resulted in different selective oxidation patterns.…”

Enhanced photocatalytic hydrogen evolution along with byproducts suppressing over Z-scheme Cd Zn1−S/Au/g-C3N4 photocatalysts under visible light

“…The cyclic voltammetry (CV) methods have been used to explore the oxidation procedure of glucose [48]. Generally, the oxidation products of glucose are gluconic acid, glucaric acid, etc [23,49]. The gluconic acid is proposed as the oxidation products considering the reaction of glucose with ÁOH as observed in Fig.…”

Photocatalytic Solar Light H2 Production by Aqueous Glucose Reforming

“…Biomass conversion is less energy demanding than water splitting. The use of glucose, glycerol, lignin, etc., as sacrificial agents, can reduce the electron/hole recombination rate and favour selectively the synthesis of high value‐added products , . There are still only a relative small number of materials that can efficiently photoreform biomass, and works dedicated to improving the efficiency of photocatalysts, especially under natural solar light irradiation, are useful.…”