Statistical optimization of photocatalytic degradation process of methylene blue dye by SnO–TiO₂–AC composite using response surface methodology

Abstract

Photocatalytic activity of bi-metal oxides SnO-TiO 2 -AC photocatalyst was evaluated in methylene blue (MB) dye degradation In this study, a three-level, four-factor, D-optimal experimental design, combined with response surface methodology, was employed to optimize the photocatalytic degradation process of MB dye in a batch reactor. Effectiveness of essential process variables: light intensity (254-400 nm), initial dye concentration (100-200 ppm), photocatalyst dose (0.5-1.5 g/L), and irradiation time (1-5 h) were investigated, modeled, and optimized successfully. To determine the process efficiency, the final concentration of dye together with degradation percentage was defined as response variables. Analysis of variance indicated that the proposed quadratic polynomial models agreed with the experimental study with R 2 and p-value of 0.9211, p < 0.001 and 0.8166, p < 0.05 for a final concentration of dye and degradation percentage, respectively. Numerical optimization was carried out based on the desirability function for maximum dye removal. Accordingly, dye removal conditions resulted in light intensity, initial dye concentration, photocatalyst dose, and irradiation time of 400 nm of visible light, 100 ppm, 1.5 g/L, and 3.77 h, respectively. Under these optimal conditions, the final dye concentration and degradation percentage were 4.713 ppm and 95.28%. According to Pareto analysis, the order of the operating variables on the dye degradation efficiency was: photocatalyst does < irradiation time < light intensity < initial concentration of dye.

Cu Atomic Subnanoclusters on TiO2 for Photocatalytic Hydrogen Evolution

“…To explore the crystal structural variations of TiO 2 and different cocatalyst-loaded TiO 2 samples, XRD and Raman characterizations were conducted, as shown in Figures S1 and S2. Bare TiO 2 , Cu 1.8 -TiO 2 (denoted as SNC-Cu/TiO 2 ), and Pt 1 -TiO 2 exhibited a typical anatase TiO 2 (JCPDS 04-013-5313, space group I 41/ amd ) pattern, and no impurity peaks were detected in Figure S1a, with three prominent diffraction peaks at 25.3°, 37.8°, and 48.0° observed, which can be indexed to (101), (004), and (200) crystal planes of anatase TiO 2 . Meanwhile, no apparent metallic diffraction peaks of Cu or Pt were observed in Cu 1.8 -TiO 2 and Pt 1 -TiO 2 , which may be attributed to the low loading amount and the noncrystalline structure of the ultrafine Cu clusters and Pt nanoparticles (NPs).…”

Cerium Oxide Nanorods Synthesized by Dalbergia sissoo Extract for Antioxidant, Cytotoxicity, and Photocatalytic Applications

“…However, the value of the interaction coefficients of the individual terms A, B, and C was found to be rather higher in comparison to the interaction term of factor AB. This further indicated that the optimization of this reaction is heavily dependent on the individual factors rather than on the interaction terms [ 38 ].…”

The Influence of SnO2 and Noble Metals on the Properties of TiO2 for Environmental Sustainability

“…The photocatalytic decomposition of MO with c 0 = 130 µM under UV irradiation on the TS_Ag nanocomposites leads to a rate constant value of 43.95 × 10 −3 min −1 , while the equivalent rate recorded under Vis irradiation was lower, at 18.52 × 10 −3 min −1 (Table 1). There are many reports in the literature where the researchers combine the synergetic effects of TiO 2 and SnO 2 in order to increase their photodegradation performance on toxic contaminants in aqueous media [12,18,45,46]. Moreover, the metal nanoparticle's presence on the semiconductor matrix provides a better tunability for visible absorption [46], stops the recombination of e − /h + pairs, and enhances e − /h + separation, leading to an improvement in the photocatalytic performance.…”