MoS_2/g-C_3N_4纳米纤维光催化降解柴油机苯系排放污染物
|
摘要
采用同轴静电纺丝法制备了MoS_2/g-C_3N_4纳米纤维,采用XRD、FTIR、XPS、UV-Vis和Raman等光谱分析技术表征了催化剂相组成和微观形貌,评价了催化剂表面化学形态和吸光特性,探讨了催化剂对甲苯的光催化降解机理,研究了MoS_2含量、光源条件、温度和催化稳定性对降解甲苯的影响规律.结果表明,在MoS_2/g-C_3N_4中掺杂适宜的MoS_2有助于提高催化剂活性,改善催化剂比表面积和孔容积.在可见光条件下,催化剂(10%MoS_2)对甲苯的降解率为90.24%.由汽车尾气中苯系污染物光催化降解应用可知,在柴油机转速为2000 r·min~(-1),油门开度(负荷)分别为25%、50%、75%和100%的条件下,10%MoS_2对苯、甲苯、乙苯、对二甲苯、间二甲苯和邻二甲苯的平均降解率分别为88.12%、90.03%、86.25%、87.12%、87.07%和87.23%,表明MoS_2/g-C_3N_4纳米纤维具有较强的光催化降解苯系物能力.
MoS_2/g-C_3N_4 composite nanofibers were prepared by the coaxial electrospinning method. The crystalline phase and microstructure of MoS_2/g-C_3N_4 catalysts were displayed by X-ray diffraction(XRD) and Fourier transform infrared spectroscopy(FTIR). Absorption characteristics and electrochemical properties of MoS_2/g-C_3N_4 catalysts were characterized by X-ray photoelectron spectroscopy(XPS), ultraviolet-visible spectrometry(UV-Vis) and Raman spectroscopy. The corresponding influence factors on MoS_2 content, light condition, temperature and repeated performance for toluene degradation rate in the photocatalytic activity device were analyzed. The results show that catalytic activity of MoS_2/g-C_3N_4 was improved through doping appropriate amount of MoS_2, and the specific surface area and pore volume of catalysts increased accordingly. with 10% MoS_2, MoS_2/g-C_3N_4 presented 90.24% photocatalytic degradation effieincy for toluene in visible-light illumination. Under four different loads(25%, 50%, 75% and 100%) and diesel engine rotational speed(2000 r·min~(-1)), average degradation rate of benzene, toluene, ethylbenzene, p-xylene, m-xylene and o-xylene were 88.12%, 90.03%, 86.25%, 87.12%, 87.07% and 87.23% respectively in visible-light illumination. Therefore, it is verified that MoS_2/g-C_3N_4 catalyst had better photocatalytic activity in reducing benzene homologues emissions from diesel engine exhaust.
MoS_2/g-C_3N_4 composite nanofibers were prepared by the coaxial electrospinning method. The crystalline phase and microstructure of MoS_2/g-C_3N_4 catalysts were displayed by X-ray diffraction(XRD) and Fourier transform infrared spectroscopy(FTIR). Absorption characteristics and electrochemical properties of MoS_2/g-C_3N_4 catalysts were characterized by X-ray photoelectron spectroscopy(XPS), ultraviolet-visible spectrometry(UV-Vis) and Raman spectroscopy. The corresponding influence factors on MoS_2 content, light condition, temperature and repeated performance for toluene degradation rate in the photocatalytic activity device were analyzed. The results show that catalytic activity of MoS_2/g-C_3N_4 was improved through doping appropriate amount of MoS_2, and the specific surface area and pore volume of catalysts increased accordingly. with 10% MoS_2, MoS_2/g-C_3N_4 presented 90.24% photocatalytic degradation effieincy for toluene in visible-light illumination. Under four different loads(25%, 50%, 75% and 100%) and diesel engine rotational speed(2000 r·min~(-1)), average degradation rate of benzene, toluene, ethylbenzene, p-xylene, m-xylene and o-xylene were 88.12%, 90.03%, 86.25%, 87.12%, 87.07% and 87.23% respectively in visible-light illumination. Therefore, it is verified that MoS_2/g-C_3N_4 catalyst had better photocatalytic activity in reducing benzene homologues emissions from diesel engine exhaust.
引文
Bai J R,Lv W H,Ni Z J,et al.2018.Integrating MoS2 on sulfur-doped porous g-C3N4 iostype heterojunction hybrids enhances visible- light photocatalytic performance[J].Journal of Alloys and Compounds,768(7):766-774
Bian H,Ji Y J,Yan J Q,et al.2018.In situ synthesis of few-layered g-C3N4 with vertically aligned MoS2 loading for boosting solar-to-hydrogen generation[J].Small,14(3):1-9
Cen J M,Wei S B,Nan H J,et al.2018.Incorporation of carbon nanotubes into graphene for highly efficient solid-phase microextraction of benzene homologues[J].Microchemical Journal,139(2):203-209
Chen R,Zhu C Z,Lu J,et al.2018.BiVO4/α-Fe2O3 catalytic degradation of gaseous benzene:Preparation,characterization and photocatalytic properties[J].Applied Surface Science,427(part B):141-147
Cheng X R,Li Y Y,Shang J M,et al.2018.Thickness-dependent phase transition and optical behavior of MoS2 films under high pressure[J].Nano Research,11(2):855-863
Devaraji P,Gopinath C S.2018.Pt-g-C3N4-(Au/TiO2):Electronically integrated nanocomposite for solar hydrogen generation[J].International Journal of Hydrogen Energy,43(2):601-613
Dhada I,Nagar P K,Sharma M,et al.2016.Photo-catalytic oxidation technology for VOC control:evaluation and risk characterization of intermediates of benzene degradation adsorbed on catalyst[J].Environmental Engineering Science,33(12):1-8
Gu Y F,Liu X T,Zhang Y.2018.Supramolecular recognition of benzene homologues in a 2D coordination polymer through variable inter-layer pi-pi interaction[J].Cryst Eng Comm,20(24):3313-3317
Guan W,Tian S C.2017.An effect of crucible volume on the microstructure and photocatalytic activity of the prepared g-C3N4[J].Journal of Nanoelectronics and Optoelectronics,12(8):781-785
胡明江.2015.CeO2-TiO2复合纳米纤维光催化降解醛酮类污染物的研究[J].环境科学学报,35(1):215-221
Liu J,Chen Y,Wang H M,et al.2017.Effects of atmosphere pretreatment on the catalytic performance of Pd/γ-Al2O3 catalyst in benzene degradation II:Crystal structure transformation of Pd active species[J].Catalysis Today,297(1):211-218
Liu Y Z,Zhang H Y,Ke J,et al.2018.0D (MoS2)/2D (g-C3N4) heterojunctions in Z-scheme for enhanced photocatalytic and electrochemical hydrogen evolution[J].Applied Catalysis B-Environmental,228(1):64-74
Masoud F,Neda M,Amir A.2018.TiO2 nanotubes/Ti plates modified by silver-benzene with enhanced photocatalytic antibacterial properties[J].New Journal of Chemistry,42(3):2058-2066
Pragati F,Sudharshan K Y,Roshan N,et al.2017.Decoration of MoS2 on g-C3N4 surface for efficient hydrogen evolution reaction[J].Electrochimica Acta,258(11):1273-1283
Ran M X,Li J R,Cui W.2018.Efficient and stable photocatalytic NO removal on C self-doped g-C3N4:electronic structure and reaction mechanism[J].Catalysis Science & Technology,8(13):3387-3394
Sajid A A,Moo H C.2017.Growth of three-dimensional flower-like SnS2 on g-C3N4 sheets as an efficient visible-light photocatalyst,photoelectrode,and electrochemical supercapacitance material[J].Sustainable Energy & Fuels,1(3):510-519
Wang T,Chen S,Wang H G,et al.2017.In-plasma catalytic degradation of toluene over different MnO2 polymorphs and study of reaction mechanism[J].Chinese Journal of Catalysis,38(5):793-803
Wang X X,Gao J P,Zhao R R,et al.2018.Preparation and photocatalytic performance of g-C3N4 nanotubes[J].Chinese Joural of Inorganic Chemistry,34(6):1059-1064
Wang Z,Deng Y Z,Shen G L,et al.2016.Catalytic degradation of benzene over nanocatalysts containing cerium and manganese[J].Chemistry Open,5(5):495-504
吴朝军,尹明彩,张尚青,等.2017.MoS2/g-C3N4复合催化剂的制备及CdSe量子点敏化产氢性能研究[J].材料导报,31(29):158-163
Xia W W,Huang F R,Wei J W.2017.Ultrasound exfoliation of g-C3N4 and hydrothermal synthesis of rGO/g-C3N4 hybrid nanocomposites with improved visible photocatalytic activities[J].Nanoscience and Nanotechnology Letters,9(11):1665-1672
徐梦秋,柴波,闫俊涛,等.2017.MoS2/g-C3N4复合材料的制备及可见光催化性能[J].无机化学学报,33(3):389-395
阎鑫,卢锦花,惠小艳,等.2018.g-C3N4/MoS2纳米片/氧化石墨烯三元复合催化剂的制备及可见光催化性能[J].无机化学学报,33(5):515-520
Yang T,Li D D,Shan X L,et al.2017.Pollution characterization,source apportionment and health risk assessment of benzene homologues in the ambient air of a typical urban area in Beijing,China[J].Asian Journal of Ecotoxicology,12(5):79-97
Yu X,Fan X L,An L,et al.2018.An insight into the crucial factors for photochemical deposition of cobalt cocatalyst on g-C3N4 photocatalyst[J].Carbon,128(2):21-30
Zhang S H,Yang Q,Li Z,et al.2017.Covalent organic frameworks as a novel fiber coating for solid-phase microextraction of volatile benzene homologues[J].Analytical and Bioanalytical Chemistry,409(13):3429-3439
Zhao N,Kong L G,Dong Y M,et al.2018.An insight into the crucial factors for photochemical deposition of cobalt cocatalyst on g-C3N4 Photocatalyst[J].ACS Applied Materials & Interfaces,10(11):9522-9531
Zhou L,Wang L Z,Lei J Y,et al.2017.Fabrication of TiO2/Co-g-C3N4 heterojunction catalyst and its photocatalytic performance[J].Catalysis Communications,29(2):125-128
Bian H,Ji Y J,Yan J Q,et al.2018.In situ synthesis of few-layered g-C3N4 with vertically aligned MoS2 loading for boosting solar-to-hydrogen generation[J].Small,14(3):1-9
Cen J M,Wei S B,Nan H J,et al.2018.Incorporation of carbon nanotubes into graphene for highly efficient solid-phase microextraction of benzene homologues[J].Microchemical Journal,139(2):203-209
Chen R,Zhu C Z,Lu J,et al.2018.BiVO4/α-Fe2O3 catalytic degradation of gaseous benzene:Preparation,characterization and photocatalytic properties[J].Applied Surface Science,427(part B):141-147
Cheng X R,Li Y Y,Shang J M,et al.2018.Thickness-dependent phase transition and optical behavior of MoS2 films under high pressure[J].Nano Research,11(2):855-863
Devaraji P,Gopinath C S.2018.Pt-g-C3N4-(Au/TiO2):Electronically integrated nanocomposite for solar hydrogen generation[J].International Journal of Hydrogen Energy,43(2):601-613
Dhada I,Nagar P K,Sharma M,et al.2016.Photo-catalytic oxidation technology for VOC control:evaluation and risk characterization of intermediates of benzene degradation adsorbed on catalyst[J].Environmental Engineering Science,33(12):1-8
Gu Y F,Liu X T,Zhang Y.2018.Supramolecular recognition of benzene homologues in a 2D coordination polymer through variable inter-layer pi-pi interaction[J].Cryst Eng Comm,20(24):3313-3317
Guan W,Tian S C.2017.An effect of crucible volume on the microstructure and photocatalytic activity of the prepared g-C3N4[J].Journal of Nanoelectronics and Optoelectronics,12(8):781-785
胡明江.2015.CeO2-TiO2复合纳米纤维光催化降解醛酮类污染物的研究[J].环境科学学报,35(1):215-221
Liu J,Chen Y,Wang H M,et al.2017.Effects of atmosphere pretreatment on the catalytic performance of Pd/γ-Al2O3 catalyst in benzene degradation II:Crystal structure transformation of Pd active species[J].Catalysis Today,297(1):211-218
Liu Y Z,Zhang H Y,Ke J,et al.2018.0D (MoS2)/2D (g-C3N4) heterojunctions in Z-scheme for enhanced photocatalytic and electrochemical hydrogen evolution[J].Applied Catalysis B-Environmental,228(1):64-74
Masoud F,Neda M,Amir A.2018.TiO2 nanotubes/Ti plates modified by silver-benzene with enhanced photocatalytic antibacterial properties[J].New Journal of Chemistry,42(3):2058-2066
Pragati F,Sudharshan K Y,Roshan N,et al.2017.Decoration of MoS2 on g-C3N4 surface for efficient hydrogen evolution reaction[J].Electrochimica Acta,258(11):1273-1283
Ran M X,Li J R,Cui W.2018.Efficient and stable photocatalytic NO removal on C self-doped g-C3N4:electronic structure and reaction mechanism[J].Catalysis Science & Technology,8(13):3387-3394
Sajid A A,Moo H C.2017.Growth of three-dimensional flower-like SnS2 on g-C3N4 sheets as an efficient visible-light photocatalyst,photoelectrode,and electrochemical supercapacitance material[J].Sustainable Energy & Fuels,1(3):510-519
Wang T,Chen S,Wang H G,et al.2017.In-plasma catalytic degradation of toluene over different MnO2 polymorphs and study of reaction mechanism[J].Chinese Journal of Catalysis,38(5):793-803
Wang X X,Gao J P,Zhao R R,et al.2018.Preparation and photocatalytic performance of g-C3N4 nanotubes[J].Chinese Joural of Inorganic Chemistry,34(6):1059-1064
Wang Z,Deng Y Z,Shen G L,et al.2016.Catalytic degradation of benzene over nanocatalysts containing cerium and manganese[J].Chemistry Open,5(5):495-504
吴朝军,尹明彩,张尚青,等.2017.MoS2/g-C3N4复合催化剂的制备及CdSe量子点敏化产氢性能研究[J].材料导报,31(29):158-163
Xia W W,Huang F R,Wei J W.2017.Ultrasound exfoliation of g-C3N4 and hydrothermal synthesis of rGO/g-C3N4 hybrid nanocomposites with improved visible photocatalytic activities[J].Nanoscience and Nanotechnology Letters,9(11):1665-1672
徐梦秋,柴波,闫俊涛,等.2017.MoS2/g-C3N4复合材料的制备及可见光催化性能[J].无机化学学报,33(3):389-395
阎鑫,卢锦花,惠小艳,等.2018.g-C3N4/MoS2纳米片/氧化石墨烯三元复合催化剂的制备及可见光催化性能[J].无机化学学报,33(5):515-520
Yang T,Li D D,Shan X L,et al.2017.Pollution characterization,source apportionment and health risk assessment of benzene homologues in the ambient air of a typical urban area in Beijing,China[J].Asian Journal of Ecotoxicology,12(5):79-97
Yu X,Fan X L,An L,et al.2018.An insight into the crucial factors for photochemical deposition of cobalt cocatalyst on g-C3N4 photocatalyst[J].Carbon,128(2):21-30
Zhang S H,Yang Q,Li Z,et al.2017.Covalent organic frameworks as a novel fiber coating for solid-phase microextraction of volatile benzene homologues[J].Analytical and Bioanalytical Chemistry,409(13):3429-3439
Zhao N,Kong L G,Dong Y M,et al.2018.An insight into the crucial factors for photochemical deposition of cobalt cocatalyst on g-C3N4 Photocatalyst[J].ACS Applied Materials & Interfaces,10(11):9522-9531
Zhou L,Wang L Z,Lei J Y,et al.2017.Fabrication of TiO2/Co-g-C3N4 heterojunction catalyst and its photocatalytic performance[J].Catalysis Communications,29(2):125-128