Effect of different climate zone’s humic and fulvic acid on aggregation of UV irradiated graphene oxide  

作　　者：Jawad Ali Xinfeng Wang Xinjie Wang Enxiang Shang Zahid Hussain Muhammad Mohiuddin Jian Zhao Xinghui Xia Yang Li 

机构地区：[1]Environment Research Institute,Shandong University,Qingdao 266237,China [2]State Key Laboratory of Water Environment Simulation,School of Environment,Beijing Normal University,Beijing 100875,China [3]College of Science and Technology,Hebei Agricultural University,Huanghua 061100,China [4]Department of Development Studies,COMSATS University Islamabad,Abbottabad Campus,Abbottabad 22060,Pakistan [5]Environment Management Consultant(EMC)Pakistan Pvt Ltd.,Karachi 75350,Pakistan

出　　处：《Frontiers of Environmental Science & Engineering》2025年第3期27-41,共15页环境科学与工程前沿(英文)

基　　金：financially supported by the National Natural Science Foundation of China(Nos.42250410319,52170024 and 21677015);the Qingdao Municipal Bureau of Human Resources and Social Security,China(No.QDBSH20220201006).

摘　　要：UV light absorption by aquatic systems affect the physicochemical characteristics of graphene oxide(GO)nanoparticles which ultimately influence its aggregation behavior in water.Regarding this research,various humic and fulvic acids(HA/FA),extracted from China’s different climate zones,were treated with 2 h UV irradiated large(~500 nm)and(~200 nm)GO in 200 mmol/L NaCl.UV irradiated GO particles displayed aggregation even at low humic acid/fulvic acid(HA/FA)concentrations ranging from 0.2 to 1.0 mgC/L,whereas pristine GO particles did not exhibit such behavior.Reduction of functional groups,containing Oxygen(C=O/C–O),via UV irradiation is responsible for this aggregation phenomenon and conversion of GO to reduced graphene oxide(rGO).Consequently,rGO exhibits lower dispersibility,facilitating its agglomeration.Moreover,both small and large-sized GO particles exhibited less aggregation in HAs compared to FAs due to large molecular weight and high polarity of HAs.Aggregation of GO was more obvious with Makou FA and Maqin HA from Plateau and Mountain climate zone and Subtropical Monsoon climate zone,respectively,owing to DOM’s lower molecular weight and aromaticity that reduced their adsorption.The application of the Derjaguin-landau-verwey-overbeek(DLVO)theory did not reveal any significant interaction energy barrier between the 2 h UV irradiated GO particles even in the presence of DOM,indicating that aggregation prevailed despite the addition of DOM.These findings highlight that UV irradiation poses a significant threat to the GO stability in aquatic environments,particularly in the presence of DOM.

关 键 词：AGGREGATION Fulvic acid Humic acid Molecular weight Reduced graphene oxide Ultraviolet irradiation 

分 类 号：X703[环境科学与工程—环境工程]