CAJ | 학술논문

通过电聚合和电沉积,将聚邻苯二胺( PoPD)/酸化多壁碳纳米管( MWNTs)网孔结构支撑的硅钨酸( SiW12)杂多阴离子成功地组装在玻碳电极( GCE)上,形成SiW12/PoPD/MWNTs/GCE。采用扫描电子显微镜和循环伏安法对不同电极复合膜进行表征,并考察BrO-3在电极上的电化学行为,发现SiW12/PoPD/MWNTs/GCE对BrO-3具有显著的电催化还原性,其作用机理是基于硅钨酸杂多阴离子复合膜在电化学还原BrO-3过程中,通过静电作用将BrO-3吸附到电极的表面,BrO-3在电极表面接受H+和硅钨酸失去的电子,依次被还原为HBrO、Br2、Br-。该电极在0.20 mol/L 磷酸盐缓冲溶液(pH=3.0)中,BrO-3的线性范围为1.0×10-8~1.0×10-4 mol/L,检出限达7.0×10-9 mol/L。此电极选择性、重现性、稳定性好,可用于实际水样中BrO-3检测,回收率在98.4%~104.1%之间,且与离子色谱方法检测结果一致,符合国家标准对水中溴酸盐的检测要求。
통과전취합화전침적,장취린분이알( PoPD)/산화다벽탄납미관( MWNTs)망공결구지탱적규오산( SiW12)잡다음리자성공지조장재파탄전겁( GCE)상,형성SiW12/PoPD/MWNTs/GCE。채용소묘전자현미경화순배복안법대불동전겁복합막진행표정,병고찰BrO-3재전겁상적전화학행위,발현SiW12/PoPD/MWNTs/GCE대BrO-3구유현저적전최화환원성,기작용궤리시기우규오산잡다음리자복합막재전화학환원BrO-3과정중,통과정전작용장BrO-3흡부도전겁적표면,BrO-3재전겁표면접수H+화규오산실거적전자,의차피환원위HBrO、Br2、Br-。해전겁재0.20 mol/L 린산염완충용액(pH=3.0)중,BrO-3적선성범위위1.0×10-8~1.0×10-4 mol/L,검출한체7.0×10-9 mol/L。차전겁선택성、중현성、은정성호,가용우실제수양중BrO-3검측,회수솔재98.4%~104.1%지간,차여리자색보방법검측결과일치,부합국가표준대수중추산염적검측요구。
Through electro-polymerization and electro-deposition, a poly ( o-phenylenediamine ) ( PoPD )/acidified multi-wall carbon nanotubes ( MWNTs) mesh structure supported silicotungstic heteropolyanion was successfully assembled on a glassy carbon electrode ( GCE) , forming a SiW12/PoPD/MWNTs/GCE. Scanning electron microscopy ( SEM ) and cyclic voltammetry ( CV ) were employed to characterize the different composite films. The electrochemical behaviors of bromate ion ( BrO-3 ) on the surfaces of different modified electrodes were investigated, indicating that the proposed SiW12/PoPD/MWNTs/GCE exhibited excellent electrocatalytic reduction activity to bromate. The mechanism is that the bromate anion is adsorbed to the surface of the electrode through electrostatic interaction, and accepts H+ and electrons lost from SiW12 on the surface, resulting in its stepwise reduction to HBrO, Br2 , and Br-. In 0. 20 mol/L phosphate buffer solution ( pH=3 . 0 ) , the modified electrode showed excellent electrochemical response property to BrO-3 with a linear range of 1. 0í10-8 ~1. 0í10-4 mol/L and a detection limit of 7. 0í10-9 mol/L. The electrode possessed good selectivity, reproducibility and stability, which can be well applied to determination of bromate content in real water samples with a recovery of 98 . 4%-104 . 1%. The accuracy of the electrode was also comparable to that of a traditional ion chromatographic method, which met the national standard for requirement of bromate detection in water, indicating that the proposed method was of valuable in practical application on fields of food safety and environmental protection.