纳米纤维素/还原氧化石墨烯光催化气凝胶的制备及其吸附降解罗丹明B  

Preparation of Cellulose Nanofibers/Reduced Graphene Oxide Photocatalytic Aerogel and Its Adsorption and Degradation of Rhodamine B

作　　者：岳一莹 潘红阳 蒋剑春[2,3] YUE Yiying;PAN Hongyang;JIANG Jianchun(College of Ecology and Environment,Nanjing Forestry University,Nanjing 210037,China;College of Chemical Engineering,Nanjing Forestry University,Nanjing 210037,China;Institute of Chemical Industry of Forest Products,CAF,Nanjing 210042,China)

机构地区：[1]南京林业大学生态与环境学院,江苏南京210037 [2]南京林业大学化学工程学院,江苏南京210037 [3]中国林业科学研究院林产化学工业研究所,江苏南京210042

出　　处：《生物质化学工程》2024年第2期1-12,共12页Biomass Chemical Engineering

基　　金：国家自然科学基金资助项目(31901274);中国博士后科学基金特别资助项目(2020T130303);中国博士后科学基金资助项目(2019M661854)。

摘　　要：以漂白木浆为原料,先经2,2,6,6-四甲基哌啶-1-氧自由基(TEMPO)氧化制得氧化纳米纤维素(TOCN),再与还原氧化石墨烯(rGO)复合制得气凝胶TOCN/rGA,然后将催化剂Ag/AgCl/石墨相氮化碳(g-C_(3)N_(4))负载在该气凝胶上,制备光催化气凝胶Ag/AgCl/g-C_(3)N_(4)@TOCN/rGA,并将其用于吸附降解罗丹明B(RhB)。通过红外光谱(FT-IR)、场发射扫描显微镜(SEM)和透射电子显微镜(TEM)对气凝胶的结构和形貌进行表征,利用X射线光电子能谱(XPS)、紫外漫反射光谱(DRS)、荧光光谱(PL)、瞬间光电流和活性物质捕获实验以及能带结构计算探讨气凝胶的光催化机理,并分析了气凝胶吸附性、光降解性能、力学强度和抗菌性。研究结果表明:Ag/AgCl/g-C_(3)N_(4)@TOCN/rGA成功制备,其具有丰富的多孔结构。rGO良好的导电性有效抑制了Ag/AgCl/g-C_(3)N_(4)光生载流子的重组,相较于Ag/AgCl/g-C_(3)N_(4),Ag/AgCl/g-C_(3)N_(4)@TOCN/rGA具有强可见光吸收,低光生载流子复合率和高瞬态光电流密度;Ag/AgCl/g-C_(3)N_(4)的负载也增大了气凝胶的平衡吸附量和机械强度:Ag/AgCl/g-C_(3)N_(4)@TOCN/rGA对RhB的平衡吸附量为2.86 mg/g,优于TOCN/rGA的平衡吸附量2.72 mg/g;在应变为70%时,Ag/AgCl/g-C_(3)N_(4)@TOCN/rGA的抗压强度为0.86 MPa,高于TOCN/rGA的抗压强度0.62 MPa。Ag/AgCl/g-C_(3)N_(4)与TOCN/rGA相互作用获得了优异的降解效果:在pH值7,光照180 min时Ag/AgCl/g-C_(3)N_(4)@TOCN/rGA对RhB降解率为95.1%,循环4次后对RhB的降解率为80.5%,120 min对大肠杆菌的抑菌率为100%。自由基捕获实验结果表明:超氧自由基(·O_(2)^(-))为复合气凝胶光催化主要活性物质。Oxidized nanocellulose(TOCN)was prepared by 2,2,6,6-tetramethylpiperidine-1-oxy radical(TEMPO)-oxidation using bleached wood pulp as raw material.Aerogel TOCN/rGA was prepared by combining by TOCN with reduced graphene oxide(rGO).On this basis,the photocatalytic aerogel Ag/AgCl/g-C_(3)N_(4)@TOCN/rGA was prepared by loading the catalyst Ag/AgCl/graphite phase carbon nitride(g-C_(3)N_(4))on the aerogel,and the aerogel was used for adsorption and degradation of Rhodamine B(RhB).The structure and morphology of the aerogel was characterized by FT-IR,SEM,and TEM.The photocatalytic mechanism of the aerogel was investigated by XPS,DRS,PL,transient photocurrent,active substance capture experiments and energy band structure calculation.Moreover,the adsorption,photodegradation,mechanical strength and antibacterial properties of the aerogel were analyzed.The results showed that Ag/AgCl/g-C_(3)N_(4)@TOCN/rGA was successfully prepared with abundant porous results.The good electrical conductivity of rGO effectively inhibits the recombination of Ag/AgCl/g-C_(3)N_(4)photogenerated carriers.Compared with Ag/AgCl/g-C_(3)N_(4),Ag/AgCl/g-C_(3)N_(4)@TOCN/rGA has stronger visible light absorption,lower photogenerated carrier recombination rate,and higher transient photocurrent density.The loading of Ag/AgCl/g-C_(3)N_(4)also increases the equilibrium adsorption capacity and mechanical strength of the aerogel:the equilibrium adsorption capacity of Ag/AgCl/g-C_(3)N_(4)@TOCN/rGA for RhB is 2.86 mg/g,which is higher than that of TOCN/rGA at 2.72 mg/g.At 70%strain,the compressive strength of Ag/AgCl/g-C_(3)N_(4)@TOCN/rGA is 0.86 MPa,which is higher than that of TOCN/rGA at 0.62 MPa.Ag/AgCl/g-C_(3)N_(4)interacting with TOCN/rGA obtains excellent degradation effects:the degradation rate of RhB by Ag/AgCl/g-C_(3)N_(4)@TOCN/rGA is 95.1%for 180 min at pH=7,and 80.5%for RhB after 4 cycles of irradiation,and the inhibition rate of Escherichia coli was 100%for 120 min.The results of free radical capture experiment show that superoxide radical(O_(2)^

关 键 词：石墨相氮化碳 气凝胶 吸附 降解 力学性质 循环利用 

分 类 号：TQ35[化学工程] X5[环境科学与工程—环境工程]