Liu Hang,Tian Siye,Liu Yanchang,Liu Junlong,Qu Zhihao,Zhang Yuhong
In this paper, Zn 2 SnO 4 -SnO 2 -ZnO (ZSO) cubic nanomaterials are prepared by a hydrothermal method, and then ZSO composites with Au nanoparticles are prepared by a water bath heating method. The Au/ZSO nanomaterials are characterized by XRD, XPS, SEM and TEM. The results of XRD and XPS shows that the prepared samples have no other impurities, and also prove the existence of Au. The cubic structure of the sample was observed by SEM. The lattice spacings of Zn 2 SnO 4 , ZnO, SnO 2 and Au were calculated from TEM images. The gas sensing properties of pure ZSO and Au/ZSO nanocomposites are compared. At the optimum working temperature of 240 °C, the response of 3%Au/ZSO nanocomposite to 100 ppm triethylamine (TEA) is as high as 1595.5. Lower detection limit is as low as 3 ppm with a response value of 35.3. Importantly, this paper proposes an efficient method for preparing Au nanoparticles supported on ZSO and a gas sensor with high sensitivity response to TEA.
In this work, a highly efficient uranium extraction method from water by the piezo catalytic reduction-oxidation process is reported by utilizing a hollow cubic shaped Zn 2 SnO 4 /SnO 2 as piezo catalyst. The electrons and holes in Zn 2 SnO 4 /SnO 2 are separated efficiently under the irradiation of ultrasound. After that, some of the piezo electrons reduce the adsorbed U(VI) to UO 2 , the others react with soluble oxygen to form H 2 O 2 , and oxidize UO 2 to generate (UO 2 )O 2 ∙2H 2 O, which could be efficiently separated from the solution. U(VI) piezo catalytic extraction rate could reach ~ 90% under the irradiation of ultrasonic waves (40 kHz, 120 W) within 5 h and only decreased by ~ 3% after four cycles. The present work advances piezo catalysis as a new route for uranium extraction from water, which may be applied in the extraction or removal of U(VI) in the U-containing wastewaters, providing new opportunities for resource-saving and environmental enhancement.
We developed a facile strategy for the fabrication of uniform Au inlaid Zn2SnO4/SnO2 hollow rounded cubes with an adjustable Au loading content using ZnSn(OH)6 as the precursor, chloroauric acid as the Au source and ascorbic acid as the reducing agent. The Au inlaid Zn2SnO4/SnO2 hollow rounded cubes show enhanced light absorption ability and reduced recombination rate of photogenerated electron–hole pairs compared with pure Zn2SnO4/SnO2. The hollow rounded cube structured Au–Zn2SnO4/SnO2 sample displays a high surface area and high dye adsorption ability. As photoanodes for DSSCs, the Au–Zn2SnO4/SnO2 hollow rounded cubes demonstrate a greatly enhanced Jsc and an improved power conversion efficiency of up to 2.04%, almost 73% higher compared to the photovoltaic conversion efficiency of pure Zn2SnO4/SnO2 based DSSCs. The greatly improved power conversion efficiency of DSSCs based on the Au inlaid Zn2SnO4/SnO2 photoanode can be attributed to the following three factors. Firstly, the localized surface plasmon resonance of Au nanoparticles plays a crucial role in the enhancement of visible light absorption. Secondly, the potential barrier on the Zn2SnO4/SnO2 surface caused by Au nanoparticles can suppress electron–hole recombination, diminish the loss of electrons during the transfer process and improve the photocurrent density. Thirdly, the enhanced photovoltaic performance can also be attributed to the unique structural characteristics of hollow rounded cubes.
Achieving highly selective, highly responsive detection of formaldehyde gas at ppb level at room temperature is highly challenging for air monitoring and life health observation. Therefore, in this paper, low-cost, easy-to-fabricate, highly responsive as well as highly selective Zn 2 SnO 4 /SnO 2 (ZTO/SnO 2 ) metal-oxide semiconductor gas sensors have been successfully prepared by using one-pot hydrothermal method . The results showed that the synergistic effect of the n-n heterojunction formed between ZTO/SnO 2 prepared by this method led to a substantial increase in the sensitivity to the target gases, and ZTO/SnO 2 -3 a higher response (291) to 100 ppm formaldehyde compared to the response values of pure samples of Zn 2 SnO 4 (20.4) and pure SnO 2 (6.99) at room temperature. In addition, the response value for formaldehyde reached about 16.5–295 times higher than that for other common hazardous gases (100 ppm) in our lives. The ZTO/SnO 2 -3 sample with 1 mol/L NaOH was homogeneous and small, exposing as much surface as possible, and the theoretical minimum detection limit was calculated to be 50 ppb. Therefore, the large specific surface area and active adsorption/interaction sites are favorable for gas sensing. This work provides an excellent way to prepare gas-sensitive characteristic sensors using NaOH to improve the surface structure.
危险品化学品经营许可证（带存储）