Artificial Solar Light-Driven APTES/TiO2 Photocatalysts for Methylene Blue Removal from Water

Abstract

A visible-light photocatalytic performance of 3-aminopropyltriethoxysilane (APTES)-modified TiO2 nanomaterials obtained by solvothermal modification under elevated pressure, followed by calcination in an argon atmosphere at 800–1000 °C, is presented for the first time. The presence of silicon and carbon in the APTES/TiO2 photocatalysts contributed to the effective delay of the anatase-to-rutile phase transformation and the growth of the crystallites size of both polymorphous forms of TiO2 during heating. Thus, the calcined APTES-modified TiO2 exhibited higher pore volume and specific surface area compared with the reference materials. The change of TiO2 surface charge from positive to negative after the heat treatment increased the adsorption of the methylene blue compound. Consequently, due to the blocking of active sites on the TiO2 surface, the adsorption process negatively affected the photocatalytic properties. All calcined photocatalysts obtained after modification via APTES showed a higher dye decomposition degree than the reference samples. For all 3 modifier concentrations tested, the best photoactivity was noted for nanomaterials calcined at 900 °C due to a higher specific surface area than materials calcined at 1000 °C, and a larger number of active sites available on the TiO2 surface compared with samples annealed at 800 °C. It was found that the optimum concentration for TiO2 modification, at which the highest dye decomposition degree was noted, was 500 mM.

Photocatalytic Inactivation of Co-Culture of E. coli and S. epidermidis Using APTES-Modified TiO2

“…As an effect, the modified TiO 2 presented a less positive zeta potential value. Similar findings were also presented in our previous work [ 43 ].…”

“…As shown in Figure 2 b, some bands in APTES-modified photocatalysts (attributed to alkyl groups, –NH 3 + , and C–N bonds) faded with the increasing calcination temperature. As confirmed in previous work, these groups were not permanently attached to the TiO 2 surface and an increase in the annealing temperature led to the destruction of these bonds [ 43 ].…”

“…The increase in the specific surface area and the total pore volume of the samples prepared at 300–500 °C could be explained by the decomposition of APTES molecules. Sienkiewicz et al [ 43 ] noted that, with the increase in the modification temperature, the APTES molecules started degrading and both the external surface of TiO 2 and pores could be unblocked.…”

Enhanced Anti‐Corrosion Performance of Carbon Steels via CeO2@BNNSs/Epoxy Resin Composite Coatings

“…Hydroxyl groups on the surface of CeO 2 react with APTES hydrolysate to form APTES‐CeO 2 , to form the APTES‐CeO 2 . [ 47 ] There emerged a chemical reaction between the OH/CO of APTES and the OH/NH 2 of PDA. [ 48 ] As a result, a favorite interconnection between CeO 2 and BNNSs occurred together with the reaction of PDA and APTES, to obtain the CeO 2 @BNNSs composite powders.…”

Flexible Nano-TiO2 Sheets Exhibiting Excellent Photocatalytic and Photovoltaic Properties by Controlled Silane Functionalization─Exploring the New Prospects of Wastewater Treatment and Flexible DSSCs

“…This indicates that optimizing the amount of the surface modifier positively affects the photocatalytic ability. Efforts were made to use silane-modified TiO 2 in photocatalytic dye degradation, 40 and attempts are being made to improve their photocatalytic efficiency. The details of the state of the art of research on silane-modified TiO 2 in photocatalytic dye degradation are summarized in Table 1 .…”