{"title":"钆掺杂对Ag3PO4可见光催化性能的影响:降解蒽醌染料的活性评价及机理研究","authors":"E. Ghazalian , N. Ghasemi , A.R. Amani-Ghadim","doi":"10.1016/j.molcata.2016.11.026","DOIUrl":null,"url":null,"abstract":"<div><p>Gadolinium (Gd)-doped silver orthophosphate (Ag<sub>3</sub>PO<sub>4</sub>) nanoparticles, with spherical morphology, were synthesized by a co-precipitation method and their photocatalytic activities were evaluated in degradation of Reactive Blue 19 (RB19), as a model organic pollutant. The synthesized Ag<sub>3</sub>PO<sub>4</sub> and Gd-doped Ag<sub>3</sub>PO<sub>4</sub> were characterized using X-ray diffraction pattern analysis, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, diffuse reflectance UV–vis spectroscopy and photoluminescence spectroscopy. In comparison with Ag<sub>3</sub>PO<sub>4</sub>, the experimental results revealed a considerable enhancement in photocatalytic activity of Gd-doped Ag<sub>3</sub>PO<sub>4</sub>. The optimum mole fraction of Gd loading in Ag<sub>3</sub>PO<sub>4</sub> was 3%. Lower photocatalytic degradation efficiency of RB19 in the presence of oxalate anion and p-benzoquinone indicated the crucial role of photogenerated holes and superoxide anion-radicals in photocatalysis on Gd-doped Ag<sub>3</sub>PO<sub>4</sub>. The enhancement of photocatalytic activity was attributed to scavenge the photoexcited electrons, and to suppress their recombination with holes and generation of active oxygen species. A nonlinear empirical kinetic model was introduced to predict the apparent first order rate constant (<em>k<sub>app</sub></em>) as a function of operational parameters, including initial RB19 concentration, Gd-doped Ag<sub>3</sub>PO<sub>4</sub> dosage and light intensity. Degradation byproducts were identified using gas chromatography-mass spectrometry and a probable pathway was proposed. Moreover, Gd-doped Ag<sub>3</sub>PO<sub>4</sub> samples displayed adequate reusability after three successive experiments.</p></div>","PeriodicalId":370,"journal":{"name":"Journal of Molecular Catalysis A: Chemical","volume":"426 ","pages":"Pages 257-270"},"PeriodicalIF":5.0620,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.molcata.2016.11.026","citationCount":"32","resultStr":"{\"title\":\"Effect of gadollunium doping on visible light photocatalytic performance of Ag3PO4: Evaluation of activity in degradation of an anthraquinone dye and mechanism study\",\"authors\":\"E. Ghazalian , N. Ghasemi , A.R. Amani-Ghadim\",\"doi\":\"10.1016/j.molcata.2016.11.026\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Gadolinium (Gd)-doped silver orthophosphate (Ag<sub>3</sub>PO<sub>4</sub>) nanoparticles, with spherical morphology, were synthesized by a co-precipitation method and their photocatalytic activities were evaluated in degradation of Reactive Blue 19 (RB19), as a model organic pollutant. The synthesized Ag<sub>3</sub>PO<sub>4</sub> and Gd-doped Ag<sub>3</sub>PO<sub>4</sub> were characterized using X-ray diffraction pattern analysis, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, diffuse reflectance UV–vis spectroscopy and photoluminescence spectroscopy. In comparison with Ag<sub>3</sub>PO<sub>4</sub>, the experimental results revealed a considerable enhancement in photocatalytic activity of Gd-doped Ag<sub>3</sub>PO<sub>4</sub>. The optimum mole fraction of Gd loading in Ag<sub>3</sub>PO<sub>4</sub> was 3%. Lower photocatalytic degradation efficiency of RB19 in the presence of oxalate anion and p-benzoquinone indicated the crucial role of photogenerated holes and superoxide anion-radicals in photocatalysis on Gd-doped Ag<sub>3</sub>PO<sub>4</sub>. The enhancement of photocatalytic activity was attributed to scavenge the photoexcited electrons, and to suppress their recombination with holes and generation of active oxygen species. A nonlinear empirical kinetic model was introduced to predict the apparent first order rate constant (<em>k<sub>app</sub></em>) as a function of operational parameters, including initial RB19 concentration, Gd-doped Ag<sub>3</sub>PO<sub>4</sub> dosage and light intensity. Degradation byproducts were identified using gas chromatography-mass spectrometry and a probable pathway was proposed. Moreover, Gd-doped Ag<sub>3</sub>PO<sub>4</sub> samples displayed adequate reusability after three successive experiments.</p></div>\",\"PeriodicalId\":370,\"journal\":{\"name\":\"Journal of Molecular Catalysis A: Chemical\",\"volume\":\"426 \",\"pages\":\"Pages 257-270\"},\"PeriodicalIF\":5.0620,\"publicationDate\":\"2017-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://sci-hub-pdf.com/10.1016/j.molcata.2016.11.026\",\"citationCount\":\"32\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Molecular Catalysis A: Chemical\",\"FirstCategoryId\":\"1\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1381116916305039\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Molecular Catalysis A: Chemical","FirstCategoryId":"1","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1381116916305039","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Effect of gadollunium doping on visible light photocatalytic performance of Ag3PO4: Evaluation of activity in degradation of an anthraquinone dye and mechanism study
Gadolinium (Gd)-doped silver orthophosphate (Ag3PO4) nanoparticles, with spherical morphology, were synthesized by a co-precipitation method and their photocatalytic activities were evaluated in degradation of Reactive Blue 19 (RB19), as a model organic pollutant. The synthesized Ag3PO4 and Gd-doped Ag3PO4 were characterized using X-ray diffraction pattern analysis, scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, diffuse reflectance UV–vis spectroscopy and photoluminescence spectroscopy. In comparison with Ag3PO4, the experimental results revealed a considerable enhancement in photocatalytic activity of Gd-doped Ag3PO4. The optimum mole fraction of Gd loading in Ag3PO4 was 3%. Lower photocatalytic degradation efficiency of RB19 in the presence of oxalate anion and p-benzoquinone indicated the crucial role of photogenerated holes and superoxide anion-radicals in photocatalysis on Gd-doped Ag3PO4. The enhancement of photocatalytic activity was attributed to scavenge the photoexcited electrons, and to suppress their recombination with holes and generation of active oxygen species. A nonlinear empirical kinetic model was introduced to predict the apparent first order rate constant (kapp) as a function of operational parameters, including initial RB19 concentration, Gd-doped Ag3PO4 dosage and light intensity. Degradation byproducts were identified using gas chromatography-mass spectrometry and a probable pathway was proposed. Moreover, Gd-doped Ag3PO4 samples displayed adequate reusability after three successive experiments.
期刊介绍:
The Journal of Molecular Catalysis A: Chemical publishes original, rigorous, and scholarly full papers that examine the molecular and atomic aspects of catalytic activation and reaction mechanisms in homogeneous catalysis, heterogeneous catalysis (including supported organometallic catalysis), and computational catalysis.