太阳能电池协同强化水钠锰矿光电催化染料降解研究
|
摘要
电催化、光催化、光电催化等电化学技术以其高效、廉价、环保等特点被认为是一种极具前途的环境污染深度净化技术,在有机废水处理等方面得以广泛应用。本文借助电化学电量控制法制备了水钠锰矿电极,通过X射线衍射(XRD)、扫描电镜(SEM)表征其物相形貌,UV-Vis漫反射吸收谱结果表明水钠锰矿对300~600 nm波长范围可见光表现出良好吸收能力,计算其直接带隙约为2.14 e V,Mott-Schottky曲线计算其平带电位约1.15 V,0.1 mol/L Na2SO4介质中载流子浓度约为3.3×1019cm-3,是良好的可见光激发n型半导体材料。同时,本文以廉价高效的太阳能电池板取代了传统电化学工作站等外加电场设备,成功实现了协同强化水钠锰矿光电催化降解作用。协同作用下甲基橙60 min降解率为90.2%,效率远高于水钠锰矿光催化(2.2%)与电极电催化(33.6%)作用,强化了水钠锰矿光电催化降解反应,节省能耗的同时显著提高了降解效率。批次循环降解实验表明第4轮降解率(86.8%)较之第1轮(90.3%)降低程度<5%,表明其具有良好长时间运行稳定性。
Electrochemical technology offers an alternative solution to many environmental problems because electrons provide a versatile, efficient, cost-effective, and clean reagent. The technology includes electrocatalysis, heterogeneous photocatalysis, photoelectrocatalytic( PEC) process and so on. Birnessite electrodes were synthesized by electrochemical method in this paper. Mineral phase and morphology were studied by X-ray Diffraction( XRD) and scanning electron microscope( SEM). UV-Vis absorption spectra demonstrated that the birnessite had a significant absorption of visible light from 300 to 600 nm and a direct band gap of 2. 14 e V. Moreover,the flat band potential was 1. 15 V and the carrier concentration was 3. 3 × 1019 cm-3 as evaluated by MottSchottky. The results demonstrate that birnessite is a great n-type visible light excitation semiconducting material. Meanwhile, a cheaper and more efficient solar cell was used to replace the traditional electrochemical devices such as electrochemical workstation, which realized an enhanced photoelectrocatalytic activity of birnessite. Methyl orange degradation rate was 90. 2 % at 60 min, which was higher than the sum of degradation rate of birnessitephotocatalysis( 2. 2%) and electrocatalysis( 33. 6%). Effective utilization of sunlight was realized and photoelectrocatalytic activity of birnessite was promoted. Moreover, energy was saved and the degradation efficiency was increased. Cyclic degradation showed that decrease degree of the fourth round degradation rate( 86. 8%) was lower than 5%, compared with the first round( 90. 3%), and this shows that it has a stability of long term operating. The results obtained by the authors provide a more energy saving, advantageous, and environmentally friendly technique for organic wastewater treatment in the field of environmental mineralogy.
Electrochemical technology offers an alternative solution to many environmental problems because electrons provide a versatile, efficient, cost-effective, and clean reagent. The technology includes electrocatalysis, heterogeneous photocatalysis, photoelectrocatalytic( PEC) process and so on. Birnessite electrodes were synthesized by electrochemical method in this paper. Mineral phase and morphology were studied by X-ray Diffraction( XRD) and scanning electron microscope( SEM). UV-Vis absorption spectra demonstrated that the birnessite had a significant absorption of visible light from 300 to 600 nm and a direct band gap of 2. 14 e V. Moreover,the flat band potential was 1. 15 V and the carrier concentration was 3. 3 × 1019 cm-3 as evaluated by MottSchottky. The results demonstrate that birnessite is a great n-type visible light excitation semiconducting material. Meanwhile, a cheaper and more efficient solar cell was used to replace the traditional electrochemical devices such as electrochemical workstation, which realized an enhanced photoelectrocatalytic activity of birnessite. Methyl orange degradation rate was 90. 2 % at 60 min, which was higher than the sum of degradation rate of birnessitephotocatalysis( 2. 2%) and electrocatalysis( 33. 6%). Effective utilization of sunlight was realized and photoelectrocatalytic activity of birnessite was promoted. Moreover, energy was saved and the degradation efficiency was increased. Cyclic degradation showed that decrease degree of the fourth round degradation rate( 86. 8%) was lower than 5%, compared with the first round( 90. 3%), and this shows that it has a stability of long term operating. The results obtained by the authors provide a more energy saving, advantageous, and environmentally friendly technique for organic wastewater treatment in the field of environmental mineralogy.
引文
Bousher A,Shen X and Edyvean R G J.1997.Removal of coloured organic matter by adsorption onto low-cost waste materials[J].Water Research,31(8):2 084~2 092.
Drits V A,Silvester E,Gorskhov A I,et al.1997.Structure of synthetic monoclinic Na-rich birnessite and hexagonal birnessite;I,Results from X-ray diffraction and selected-area electron diffraction[J].A-merican Mineralogist,82:946~961.
Hai F I,Yamamoto K and Fukushi K.2007.Hybrid treatment systems for dye wastewater[J].Critical Reviews in Environmental Science and Technology,37(4):315~377.
Hou J,Li Y,Mao M,et al.2014.Tremendous effect of the morphology of birnessite-type manganese oxide nanostructures on catalytic activity[J].ACS Applied Materials&Interfaces,6(17):14 981~14 987.
Hsu Y K,Chen Y C,Lin Y G,et al.2012.Birnessite-t Hype manganese oxides nanosheets with hole acceptor assisted photoelectrochemical activity in response to visible light[J].Journal of Materials Chemistry,22(6):2 733~2 739.
Kwon K D,Refson K and Sposito G.2009.On the role of Mn(Ⅳ)vacancies in the photoreductive dissolution of hexagonal birnessite[J].Geochimica et Cosmochimica Acta,73(14):4 142~4 150.
Kleiman-Shwarsctein A,Huda M N,Walsh A,et al.2009.Electrodeposited aluminum-dopedα-Fe2O3photoelectrodes:experiment and theory[J].Chemistry of Materials,22(2):510~517.
Kuramitz H,Matsushita M and Tanaka S.2004.Electrochemical removal of bisphenol A based on the anodic polymerization using a column type carbon fiber electrode[J].Water Research,38(9):2 331~2 338.
Lu Anhuai.1999.The application of environmental mineral materials to the treatment of contaminated soil,water and air[J].Acta Petrologica et Mineralogica,18:293~299(in Chinese with English abstract).
Lu Anhuai,Lu Xiaoying,Ren Ziping,et al.2000.New advances in environmental mineralogy of natural oxides and hydroxides of iron and manganese[J].Earth Science Frontiers,7(2):473~483(in Chinese with English abstract).
Martinez-Huitle C A and Ferro S.2006.Electrochemical oxidation of organic pollutants for the wastewater treatment:direct and indirect processes[J].Chemical Society Reviews,35(12):1 324~1 340.
Nakayama M,Kanaya T,Lee J W,et al.2008.Electrochemical synthesis of birnessite-type layered manganese oxides for rechargeable lithium batteries[J].Journal of Power Sources,179(1):361~366.
Nakayama M,Nishiyama M,Shamoto M,et al.2012.Cathodic synthesis of birnessite-type layered manganese oxides for electrocapacitive catalysis[J].Journal of The Electrochemical Society,159(8):1 176~1 182.
Neumann-Spallart M,Shinde S S,Mahadik M,et al.2013.Photoelectro chemical degradation of selected aromatic molecules[J].Electrochim.Acta.,111(6):830~836.
Oh E J,Kim T W,Lee K M,et al.2010.Unilamellarnanosheet of layered manganese cobalt nickel oxide and its heterolayered film with polycations[J].ACS Nano,4(8):4 437~4 444.
Pagga U and Taeger K.1994.Development of a method for adsorption of dyestuffs on activated sludge[J].Water Research,28(5):1 051~1 057.Panizza M and Cerisola G.2009.Direct and mediated anodic oxidation of organic pollutants[J].Chemical Reviews,109(12):6 541~6 569.
Pinaud B A,Chen Z,Abram D N,et al.2011.Thin films of sodium birnessite-type Mn O2:optical properties,electronic band structure,and solar photoelectrochemistry[J].The Journal of Physical Chemistry C,115(23):11 830~11 838.
Rajeshwar K,Ibanez J G and Swain G M.1994.Electrochemistry and the environment[J].Journal of Applied Electrochemistry,24(11):1 077~1 091.
Ren Guiping,Sun Manyi,Lu Anhuai,et al.2017.Photoelectrochemical activity in response to visible light of nano-birnessite and photoelectrocatalytic activity towards degradation of methyl orange[J].Acta Mineralogica Sinica,37(4):373~379(in Chinese with English abstract).
Rodgers J D and Bunce N J.2001.Electrochemical treatment of 2,4,6-trinitrotoluene and related compounds[J].Environmental Science&Technology,35(2):406~410.
Sakai N,Ebina Y,Takada K,et al.2005.Photocurrent generation from semiconducting manganese oxide nanosheets in response to visible light[J].The Journal of Physical Chemistry B,109(19):9 651~9 655.
Sherman D M.2005.Electronic structures of iron(Ⅲ)and manganese(Ⅳ)(hydr)oxide minerals:Thermodynamics of photochemical reductive dissolution in aquatic environments[J].Geochimica et Cosmochimica Acta,69(13):3 249~3 255.
Vinodgopal K,Hotchandani S and Kamat P V.1993.Electrochemically assisted photocatalysis.Ti O2particulate film electrodes for photocatalytic degradation of 4-chlorophenol[J].Journal of Physical Chemistry(United States),97(35).
Zhang H,Ding H,Wang X,et al.2016.Photoelectrochemical performance of birnessite films and photoelectrocatalytic activity toward oxidation of phenol[J].Journal of Environmental Sciences,762:9~17.
鲁安怀.1999.环境矿物材料在土壤,水体,大气污染治理中的利用[J].岩石矿物学杂志,18(4):292~300.
鲁安怀,卢晓英,任子平,等.2000.天然铁锰氧化物及氢氧化物环境矿物学研究[J].地学前缘,7(2):473~483.
任桂平,孙曼仪,鲁安怀,等.2017.纳米水钠锰矿可见光光电化学响应与甲基橙降解活性[J].矿物学报,37(4):373~379.
Drits V A,Silvester E,Gorskhov A I,et al.1997.Structure of synthetic monoclinic Na-rich birnessite and hexagonal birnessite;I,Results from X-ray diffraction and selected-area electron diffraction[J].A-merican Mineralogist,82:946~961.
Hai F I,Yamamoto K and Fukushi K.2007.Hybrid treatment systems for dye wastewater[J].Critical Reviews in Environmental Science and Technology,37(4):315~377.
Hou J,Li Y,Mao M,et al.2014.Tremendous effect of the morphology of birnessite-type manganese oxide nanostructures on catalytic activity[J].ACS Applied Materials&Interfaces,6(17):14 981~14 987.
Hsu Y K,Chen Y C,Lin Y G,et al.2012.Birnessite-t Hype manganese oxides nanosheets with hole acceptor assisted photoelectrochemical activity in response to visible light[J].Journal of Materials Chemistry,22(6):2 733~2 739.
Kwon K D,Refson K and Sposito G.2009.On the role of Mn(Ⅳ)vacancies in the photoreductive dissolution of hexagonal birnessite[J].Geochimica et Cosmochimica Acta,73(14):4 142~4 150.
Kleiman-Shwarsctein A,Huda M N,Walsh A,et al.2009.Electrodeposited aluminum-dopedα-Fe2O3photoelectrodes:experiment and theory[J].Chemistry of Materials,22(2):510~517.
Kuramitz H,Matsushita M and Tanaka S.2004.Electrochemical removal of bisphenol A based on the anodic polymerization using a column type carbon fiber electrode[J].Water Research,38(9):2 331~2 338.
Lu Anhuai.1999.The application of environmental mineral materials to the treatment of contaminated soil,water and air[J].Acta Petrologica et Mineralogica,18:293~299(in Chinese with English abstract).
Lu Anhuai,Lu Xiaoying,Ren Ziping,et al.2000.New advances in environmental mineralogy of natural oxides and hydroxides of iron and manganese[J].Earth Science Frontiers,7(2):473~483(in Chinese with English abstract).
Martinez-Huitle C A and Ferro S.2006.Electrochemical oxidation of organic pollutants for the wastewater treatment:direct and indirect processes[J].Chemical Society Reviews,35(12):1 324~1 340.
Nakayama M,Kanaya T,Lee J W,et al.2008.Electrochemical synthesis of birnessite-type layered manganese oxides for rechargeable lithium batteries[J].Journal of Power Sources,179(1):361~366.
Nakayama M,Nishiyama M,Shamoto M,et al.2012.Cathodic synthesis of birnessite-type layered manganese oxides for electrocapacitive catalysis[J].Journal of The Electrochemical Society,159(8):1 176~1 182.
Neumann-Spallart M,Shinde S S,Mahadik M,et al.2013.Photoelectro chemical degradation of selected aromatic molecules[J].Electrochim.Acta.,111(6):830~836.
Oh E J,Kim T W,Lee K M,et al.2010.Unilamellarnanosheet of layered manganese cobalt nickel oxide and its heterolayered film with polycations[J].ACS Nano,4(8):4 437~4 444.
Pagga U and Taeger K.1994.Development of a method for adsorption of dyestuffs on activated sludge[J].Water Research,28(5):1 051~1 057.Panizza M and Cerisola G.2009.Direct and mediated anodic oxidation of organic pollutants[J].Chemical Reviews,109(12):6 541~6 569.
Pinaud B A,Chen Z,Abram D N,et al.2011.Thin films of sodium birnessite-type Mn O2:optical properties,electronic band structure,and solar photoelectrochemistry[J].The Journal of Physical Chemistry C,115(23):11 830~11 838.
Rajeshwar K,Ibanez J G and Swain G M.1994.Electrochemistry and the environment[J].Journal of Applied Electrochemistry,24(11):1 077~1 091.
Ren Guiping,Sun Manyi,Lu Anhuai,et al.2017.Photoelectrochemical activity in response to visible light of nano-birnessite and photoelectrocatalytic activity towards degradation of methyl orange[J].Acta Mineralogica Sinica,37(4):373~379(in Chinese with English abstract).
Rodgers J D and Bunce N J.2001.Electrochemical treatment of 2,4,6-trinitrotoluene and related compounds[J].Environmental Science&Technology,35(2):406~410.
Sakai N,Ebina Y,Takada K,et al.2005.Photocurrent generation from semiconducting manganese oxide nanosheets in response to visible light[J].The Journal of Physical Chemistry B,109(19):9 651~9 655.
Sherman D M.2005.Electronic structures of iron(Ⅲ)and manganese(Ⅳ)(hydr)oxide minerals:Thermodynamics of photochemical reductive dissolution in aquatic environments[J].Geochimica et Cosmochimica Acta,69(13):3 249~3 255.
Vinodgopal K,Hotchandani S and Kamat P V.1993.Electrochemically assisted photocatalysis.Ti O2particulate film electrodes for photocatalytic degradation of 4-chlorophenol[J].Journal of Physical Chemistry(United States),97(35).
Zhang H,Ding H,Wang X,et al.2016.Photoelectrochemical performance of birnessite films and photoelectrocatalytic activity toward oxidation of phenol[J].Journal of Environmental Sciences,762:9~17.
鲁安怀.1999.环境矿物材料在土壤,水体,大气污染治理中的利用[J].岩石矿物学杂志,18(4):292~300.
鲁安怀,卢晓英,任子平,等.2000.天然铁锰氧化物及氢氧化物环境矿物学研究[J].地学前缘,7(2):473~483.
任桂平,孙曼仪,鲁安怀,等.2017.纳米水钠锰矿可见光光电化学响应与甲基橙降解活性[J].矿物学报,37(4):373~379.