Electrospun Ag-TiO₂ Nanofibers for Photocatalytic Glucose Conversion to High-Value Chemicals

Abstract

TiO 2 nanofibers were fabricated by combination of sol−gel and electrospinning techniques. Ag-doped TiO 2 nanofibers with different Ag contents were prepared by two different methods (in situ electrospinning or wetness impregnation of Ag on TiO 2 nanofibers) and heat treated at 500 °C for 2 h under an air or N 2 atmosphere. The obtained catalysts were characterized by field emission scanning electron microscopy, X-ray diffraction, photoluminescence, and N 2 adsorption analyzed by the Brunauer− Emmett−Teller (BET) method. Photocatalytic glucose conversions with electrospun TiO 2 and Ag-doped TiO 2 nanofibers for production of high-value products were carried out. From different doping methods, the results indicated that 1 wt % Ag-TiO 2 nanofibers prepared by an in situ method with calcination under N 2 achieved the highest glucose conversion (85.49%). From several Ag loading contents (i.e., 0, 1, 2, and 4 wt %) in Ag-doped TiO 2 nanofibers, the nanofibers exhibited different glucose conversions [in order of 2 wt % (99.65%) > 1 wt % (85.49%) > 4 wt % (77.72%) > 0 wt % (29.64%)]. Arabinose, xylitol, gluconic acid, and formic acid were found as the high-value chemicals with the photocatalytic reaction of TiO 2 and Ag-doped TiO 2 nanofibers under UVA irradiation. Product yields of each converted chemicals from different photocatalysts from different Ag loading contents showed relatively same trends with the glucose conversion. From all results, it can be concluded that the good characteristics of 2 wt % Ag-TiO 2 nanofibers such as the smallest anatase crystallite size (8.25 nm) and the highest specific surface area (S BET = 53.69 m 2 / g) promoted the highest photocatalytic activity. Additionally, TiO 2 and Ag-doped TiO 2 nanofibers exhibited higher photocatalytic performance for glucose conversion than commercial TiO 2 (P25) and synthesized TiO 2 nanoparticles. Finally, Ag-doped TiO 2 nanofibers showed recycling ability with high photocatalytic glucose conversion after four-time use.

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

“…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.…”

“…A number of studies have been reported for conversion of sugars to several chemicals, for example, gluconic acid, formic acid, arabinose, and arabitol. 10 , 14 , 15 In addition, xylitol was also found from photocatalytic glucose conversion. 15 …”

Synthesis and Characterization of ZnO-TiO2/Carbon Fiber Composite with Enhanced Photocatalytic Properties

“…Figure 4 displays the XRD spectra of various samples. The XRD spectra of TiO 2 NFs showed several peaks at 2θ values of 27.35°, 36.0°, 41.2°, 54.25°, 56.55°, 62.75°, 63.9°, and 68.95°, which correspond to (1 1 0), (1 0 1), (1 1 1), (2 1 1), (2 2 0), (0 0 2), (3 1 0), and (3 0 1) crystal plane of rutile, respectively [ 31 , 42 ]. Similarly, the peaks at 25°, 38°, and 47.89° matched with the crystal planes of (1 0 1), (0 0 4), and (2 0 0) anatase TiO 2 , respectively [ 31 , 43 ].…”

Solar-Powered Photodegradation of Pollutant Dyes Using Silver-Embedded Porous TiO2 Nanofibers

“…Despite numerous precedents reporting on dye pollutant decomposition with TiO 2 nanocomposites, the utilization of Ag NPs-embedded TiO 2 nanofibers is scarce for this purpose [ 33 , 34 , 35 ]. Hence, these nanofibers were assessed in this study for their ability to harness solar energy and degrade two representative organic dyes, namely RhB and MO, providing us with valuable insights on the photocatalyst’s performance on xanthene and azo classes of dye, respectively.…”