Photocatalytic Reduction of Cr(VI) on a 3.0% Au/Sr_0.70Ce_0.20WO₄ Photocatalyst

Abstract

Herein, a 3.0%-Au/Sr 0.70 Ce 0.20 WO 4 sample was prepared for the photocatalytic reduction of the Cr 2 O 7 2– ion. The photocatalyst was characterized by X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and ultraviolet–visible diffuse reflectance spectra. The Sr 0.70 Ce 0.20 WO 4 sample presented a photocatalytic reduction activity that is better than those of the Ce-doped sample and the intrinsic sample. Thereafter, different metal elements, Cu, Ag, Au, and Pt, were used as cocatalysts, which were loaded on the Sr 0.70 Ce 0.20 WO 4 sample. The 3.0%-Au/Sr 0.70 Ce 0.20 WO 4 photocatalyst showed optimal photocatalytic reduction activity in a 8 vol % methanol solution (pH = 7) under visible light irradiation. The kinetic constant of the optimal one is 0.0039 min –1 , which is 1.86 times that of the Sr 0.70 Ce 0.20 WO 4 sample. The photocatalyst is stable enough after a 24 h photocatalytic experiment.

AgO@InGaZnO4 composites for environmental photocatalysis

“…For oxide photocatalysts, both doping and compounding strategies are commonly used to enhance photocatalytic performance. The performance of our previously reported oxide photocatalysts Sr 0.70 Ce 0.20 WO 4 ‐3 %Au, [33] Bi 2 InTaO 7 ‐4.5 %Ag, [34] and Bi 2 GaTaO 7 ‐4 %Ag [34] in the photoreduction of dichromate was relatively low, and the results of this experiment were relatively high. This is mainly attributed to the characteristics of the materials themselves and the optimization of the experimental conditions, including the adjustment of the acidity of the solution and the type of photogenerated hole trapping agent.…”

Synthesis of Zn0.1Sn0.1Cd0.8Sx Solid Solutions for Photocatalytic Reduction of Cr(VI): Bandgap Structure and Sulfur Vacancy Regulation

“…As shown in Figure 7a, approximately 20%, 12%, 46%, and 72% of the Cr(VI) reduction efficiency were inhibited by adding AgNO 3 , NBT, L‐his, and AO after visible light irradiation for 3 min. It indicated that e − , O 2 ⋅ − , 1 O 2 , and h + were all involved and h + played a major role in the Cr(VI) reduction [40,41] . In addition, the Cr(VI) reduction efficiency displayed no apparent change by adding TBA, implying that •OH barely participated in the photocatalytic reduction process.…”

“…It indicated that e À , O 2 *À , 1 O 2 , and h + were all involved and h + played a major role in the Cr(VI) reduction. [40,41] In addition, the Cr(VI) reduction efficiency displayed no apparent change by adding TBA, implying that * OH barely participated in the photocatalytic reduction process.…”

Two Novel Visible‐Light‐Active Borate Composites Photocatalysts: 2 %Pt/Gd0.85Ce0.15B5O9 and 2.5 %CuO/Gd0.90Ce0.10B5O9

“…The decrease in photocatalytic reduction activity is mainly caused by the generated Cr 2 O 3 covering the surface of the photocatalyst. [30] In the photodegradation reaction, the kinetic constants of GdB 5 O 9 , Gd 0.90 Ce 0.10 B 5 O 9 , 2.5 %CuO/Gd 0.90 Ce 0.10 B 5 O 9 and P25 were 0.0036, 0.0050, 0.0150 and 0.0137 min À 1 , respectively (see Table S2). The experimental results show that 2.5 %CuO/ Gd 0.90 Ce 0.10 B 5 O 9 is the best sample when adjusting the amount of CuO used and replacing other metal composite materials.…”