Ag-AgIO3改性BiOI光催化剂湿法脱除气态单质汞

周普阳; 张新民; 张安超; 王怡超; 苏胜; 李海霞; 向军

PDF(1445 KB)

中国环境科学 ›› 2020, Vol. 40 ›› Issue (11) : 4703-4711.

大气污染与控制

Ag-AgIO₃改性BiOI光催化剂湿法脱除气态单质汞

周普阳¹, 张新民¹, 张安超¹, 王怡超¹, 苏胜², 李海霞¹, 向军²

作者信息 +

Wet process of gaseous Hg⁰ removal by Ag-AgIO₃ modified BiOI photocatalyst

ZHOU Pu-yang¹, ZHANG Xin-min¹, ZHANG An-chao¹, WANG Yi-chao¹, SU Sheng², LI Hai-xia¹, XIANG Jun²

Author information +

文章历史 +

摘要

采用沉积沉淀-光还原法制备了不同AgIO₃含量的BiOI光催化剂，利用X射线衍射、N₂吸附-脱附、扫描电子显微镜、X射线光电子能谱、紫外-可见漫反射光谱和电子自旋共振对其物理化学结构进行表征，在光催化反应器上研究了AgIO₃负载量、光照、溶液温度、pH值、SO₂和NO对气态单质汞（Hg⁰）去除性能的影响.结果表明，与BiOI相比，Ag-AgIO₃改性后光催化剂的脱汞性能大幅提高.当AgIO₃负载量为4wt.%时，光催化剂的脱汞效率高达98%.与NO相比，SO₂对脱汞性能的抑制作用更大.由于Ag和AgIO₃在BiOI表面的高度分散性，Ag-AgIO₃（4%） BiOI的可见光吸收性能明显提高.荧光灯辐照与Ag-AgIO₃/BiOI光催化剂协同会产生大量的活性物种.在Ag-AgIO₃/BiOI光催化剂的高效脱汞体系中，超氧阴离子自由基（·O₂^-）为最主要的活性物质，而空穴（h⁺）和羟基自由基（·OH）次之.

Abstract

A series of Ag-AgIO₃/BiOI photocatalysts were successfully synthesized by a coprecipitation-photoreduction method and characterized by X-ray diffraction (XRD), N₂ adsorption-desorption, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS) and electron spin resonance (ESR). The effects of AgIO₃ content, fluorescent lamp (FSL) irradiation, solution temperature, pH value, SO₂ and NO on Hg⁰ removal were investigated in a photocatalytic reactor. In comparison to BiOI, Ag-AgIO₃ photocatalyst exhibited an enhanced fluorescent-light-driven photocatalytic activity for Hg⁰ removal. When the loading of AgIO₃ was 4wt.%, the removal efficiency of the Ag-AgIO₃/BiOI photocatalyst was as high as 98%. Compared with NO, the inhibitory effect of SO₂ on Hg⁰ removal efficiency became predominant. Due to the high dispersibility of Ag and AgIO₃ on the surface of BiOI, the visible light absorption performance of Ag-AgIO₃(4%)BiOI was significantly improved. The combination of fluorescent lamp irradiation and Ag-AgIO₃/BiOI photocatalyst could produce a large number of active species. The mechanism showed that in the efficient mercury removal system of the Ag-AgIO₃/BiOI photocatalyst, the superoxide radical (·O₂^-) was the most important active material, and the holes (h⁺) and hydroxyl radical (·OH) were the secondary factors.

导出引用

周普阳, 张新民, 张安超, 王怡超, 苏胜, 李海霞, 向军. Ag-AgIO₃改性BiOI光催化剂湿法脱除气态单质汞[J]. 中国环境科学. 2020, 40(11): 4703-4711

ZHOU Pu-yang, ZHANG Xin-min, ZHANG An-chao, WANG Yi-chao, SU Sheng, LI Hai-xia, XIANG Jun. Wet process of gaseous Hg⁰ removal by Ag-AgIO₃ modified BiOI photocatalyst[J]. China Environmental Science. 2020, 40(11): 4703-4711

中图分类号： X511

参考文献

[1] Zhao Y, Hao R L, Guo Q. A novel pre-oxidation method for elemental mercury removal utilizing a complex vaporized absorbent[J]. Journal of Hazardous Materials, 2014,280:118-126.
[2] Shen B X, Zhu S W, Zhang X, et al. Simultaneous removal of NO and Hg⁰ using Fe and Co co-doped Mn-Ce/TiO₂ catalysts[J]. Fuel, 2018,224:241-249.
[3] Zhang S B, Zhao Y C, Yang J P, et al. Fe-modified MnO_X/TiO₂ as the SCR catalyst for simultaneous removal of NO and mercury from coal combustion flue gas[J]. Chemical Engineering Journal, 2018,348:618-629.
[4] Cho J H, Eom Y, Jeon S H, et al. A pilot-scale TiO₂ photocatalytic system for removing gas-phase elemental mercury at Hg-emitting facilities[J]. Journal of Industrial and Engineering Chemistry, 2013,19:144-149.
[5] Li Y, Wu C Y. Role of moisture in adsorption, photocatalytic oxidation, and reemission of elemental mercury on a SiO₂-TiO₂ nanocomposite[J]. Environmental Science & Technology, 2006,40:6444-6448.
[6] Wu J, Li C E, Zhao X Y, et al. Photocatalytic oxidation of gas-phase Hg⁰ by CuO/TiO₂[J]. Applied Catalysis B:Environmental, 2015,176-177:559-569.
[7] Wang L L, Zhao Y C, Zhang J Y. Electrospun cerium-based TiO₂ nanofibers for photocatalytic oxidation of elemental mercury in coal combustion flue gas[J]. Chemosphere, 2017,185:690-698.
[8] 彭小明,罗文栋,胡玉瑛,等.磷掺杂的介孔石墨相氮化碳光催化降解染料[J]. 中国环境科学, 2019,39(8):3277-3285. Peng X M, Luo W D, Hu Y Y, et al. Study on the photocatalytic degradation of dyes by phosphorus doped mesoporous graphite carbon nitride[J]. China Environmental Science, 2019,39(8):3277-3285.
[9] 张喜.新型卤化氧铋BiOX (X=Cl, Br, I)光催化剂的合成、表征及催化性能研究[D]. 武汉:华中师范大学, 2010. Zhang X. Synthesis, characterization and photocatalytic activity of BiOX (X=Cl, Br, I) photocatalysts[D]. Wuhan:Central China Normal University, 2010.
[10] Hu Y Y, Li Z K, Yang J H, et al. Degradation of methylparaben using BiOI-hydrogel composites activated peroxymonosulfate under visible light irradiation[J]. Chemical Engineering Journal, 2019,360:200-211.
[11] Lan H C, Zhang G, Zhang H W, et al. Solvothermal synthesis of BiOI flower-like microspheres for efficient photocatalytic degradation of BPA under visible light irradiation[J]. Catalysis Communications, 2017,98:9-12.
[12] Chen J F, Hu C, Deng Z, et al. Insight into visible light-driven photocatalytic performance of direct Z-scheme Bi₂WO₆/BiOI composites constructed in-situ[J]. Chemical Physics Letters, 2019, 716:134-141.
[13] Cai L, Yao J W, Li J B, et al. Sonochemical synthesis of BiOI-TiO₂ heterojunction with enhanced visible-light-driven photocatalytic activity[J]. Journal of Alloys and Compounds, 2019,783:300-309.
[14] Ramasamy Raja V, Karthika A, Suganthi A, et al. Facile synthesis of MnWO₄/BiOI nanocomposites and their efficient photocatalytic and photoelectrochemical activities under the visible-light irradiation[J]. Journal of Science:Advanced Materials and Devices, 2018,3:331-341.
[15] 李成伟,张安超,宋军,等.Ag/BiOI光催化剂湿法脱除烟气中气态单质汞性能及机理[J]. 化工进展, 2018,37(4):1442-1450. Li C W, Zhang A C, Song J, et al. Mechanism and performance of wet process to remove gaseous elemental mercury from flue gas using Ag/BiOI photocatalyst[J]. Chemical Industry and Engineering Progress, 2018,37(4):1442-1450.
[16] Lv J X, Liu X M, Li P C, et al. AgI loading BiOI composites with enhanced photodegradation efficiency for bisphenol A under simulated solar light[J]. Science of the Total Environment, 2019,669:194-204.
[17] Cao Q W, Zheng Y F, Song X C. Enhanced visible-light-driven photocatalytic degradation of RhB by AgIO₃/WO₃ composites[J]. Journal of the Taiwan Institute of Chemical Engineers, 2017,70:359-365.
[18] Cao Q W, Zheng Y F, Song X C. Facile synthesis of AgIO₃/AgBr composite with enhanced photocatalytic activity under visible-light irradiation[J]. Journal of the Taiwan Institute of Chemical Engineers, 2017,75:141-147.
[19] Mousavi M, Habibi-Yangjeh A. Magnetically recoverable highly efficient visible-light-active g-C₃N₄/Fe₃O₄/Ag₂WO₄/AgBr nanocomposites for photocatalytic degradations of environmental pollutants[J]. Advanced Powder Technology, 2018,29:94-105.
[20] Liu H, Cao W R, Su Y, et al. Characterization and photocatalytic performance of novel visible-light-induced Ag/BiOI[J]. Applied Catalysis B:Environmental, 2012,111-112:271-279.
[21] Yao X, Liu X. One-pot synthesis of ternary Ag₂CO₃/Ag/AgCl photocatalyst in natural geothermal water with enhanced photocatalytic activity under visible light irradiation[J]. Journal of Hazardous Materials, 2014,280(49):260-268.
[22] Zhang A C, Zhang L X, Lu H, et al. Facile synthesis of ternary Ag/AgBr-Ag₂CO₃ hybrids with enhanced photocatalytic removal of elemental mercury driven by visible light[J]. Journal of Hazardous Materials, 2016,314:78-87.
[23] Liu Y X, Zhou J F, Zhang Y C, et al. Removal of Hg⁰ and simultaneous removal of Hg⁰/SO₂/NO in flue gas using two Fenton-like reagents in a spray reactor[J]. Fuel, 2015,145:180-188.
[24] Zhao Y, Xue F M, Zhao X C, et al. Experimental study on elemental mercury removal by diperiodatonickelate (IV) solution[J]. Journal of Hazardous Materials, 2013,260:383-388.
[25] Liu Y X, Liu Z Y, Zhao L, et al. Removal of NO in flue gas using vacuum ultraviolet light/ultrasound/chlorine in a VUV-US coupled reactor[J]. Fuel Processing Technology, 2018,169:226-235.
[26] 邢微波,路好,张安超,等.Ag/AgCl可见光催化剂湿法脱除烟气中单质汞[J]. 中国环境科学, 2017,37(2):503-510. Xing W B, Lu H, Zhang A C, et al. Wet process of elemental mercury removal from flue gas using Ag/AgCl photocatalyst under visible light[J]. China Environmental Science, 2017,37(2):503-510.
[27] Xiong J, Zeng H, Chen C, et al. Hierarchical p-n heterostructure BiOI@ZnTi-LDH for Cr(VI) reduction under visible light[J]. Journal of Alloys and Compounds, 2020,833:154898.
[28] Zeng C, Huang H W, Dong F, et al. Dual redox couples Ag/Ag⁺ and I^-/(IO₃)^- self-sacrificed transformation for realizing multiplex hierarchical architectures with universally powerful photocatalytic performance[J]. Applied Catalysis B:Environmental, 2017,200:620-632.
[29] Zhang G Q, Ji S, Zhang Y F, et al. Facile synthesis of p-n heterojunction of phosphorus doped TiO₂ and BiOI with enhanced visible-light photocatalytic activity[J]. Solid State Communications, 2017,259:34-39.
[30] Li Y F, Li K, Yang Y, et al. Ultrathin g-C₃N₄ nanosheets coupled with AgIO₃as highly efficient heterostructured photocatalysts for enhanced visible-light photocatalytic activity[J]. Chemistry-A European Journal, 2015,21:17739-17747.
[31] Zhang L X, Zhang A C, Lu H, et al. Magnetically separable AgI-BiOI/CoFe₂O₄ hybrid composites for Hg⁰ removal:characterization, activity and mechanism[J]. RSC Advances, 2017,7:31448-31456.
[32] Cao Q W, Zheng Y F, Yin H Y, et al. A novel AgI/AgIO₃ heterojunction with enhanced photocatalytic activity for organic dye removal[J]. Journal of Materials Science, 2016,51:4559-4565.
[33] 赵洪飞,陈林,贺凤婷,等.碳纳米管/BiOBr复合材料的制备及其光催化性能.[J]. 中国环境科学, 2019,39(11):4704-4711. Zhao H F, Chen L, He F T, et al. Preparation and photocatalytic property of carbon nanotubes/BiOBr composite[J]. China Environmental Science, 2019,39(11):4704-4711.
[34] Cao J, Xu B, Luo B, et al. Novel BiOI/BiOBr heterojunction photocatalysts with enhanced visible light photocatalytic properties[J]. Catalysis Communications, 2011,13:63-68.