Hexavalent chromium(Cr(VI))compound is useful to various industries but is toxic and carcinogenic.In this research work,we fab-ricate an amperometric sensor for the determination of Cr(VI),using a titanium dioxide(TiO...Hexavalent chromium(Cr(VI))compound is useful to various industries but is toxic and carcinogenic.In this research work,we fab-ricate an amperometric sensor for the determination of Cr(VI),using a titanium dioxide(TiO2)-reduced graphene oxide(rGO)composite as the sensing element.The composite was synthesized following sol−gel chemistry,yielding TiO2 nanoparticles of~50 nm in size,immobilized on chemically exfoliated rGO sheets.The composite was employed in a 3-electrode electrochemical cell and operated in an amperometric mode,exhibiting good responses to the 50 to 500 ppb Cr(VI).Our best result from pH 3 Mcilvane’s buffer medium reveals the sensitivity of 9.12×10−4 ppb−1 and a detection limit of 6 ppb with no signal interference from 200 ppm Ca(II),150 ppm Mg(II),and 50 ppb Pb(II).The excellent results of the TiO2-rGO sensor can be attributed to synergic effects between TiO2 and rGO,resulting from the presence of n-p heterojunctions and the formation of the TiO2 nanoparticles on rGO.展开更多
文摘Hexavalent chromium(Cr(VI))compound is useful to various industries but is toxic and carcinogenic.In this research work,we fab-ricate an amperometric sensor for the determination of Cr(VI),using a titanium dioxide(TiO2)-reduced graphene oxide(rGO)composite as the sensing element.The composite was synthesized following sol−gel chemistry,yielding TiO2 nanoparticles of~50 nm in size,immobilized on chemically exfoliated rGO sheets.The composite was employed in a 3-electrode electrochemical cell and operated in an amperometric mode,exhibiting good responses to the 50 to 500 ppb Cr(VI).Our best result from pH 3 Mcilvane’s buffer medium reveals the sensitivity of 9.12×10−4 ppb−1 and a detection limit of 6 ppb with no signal interference from 200 ppm Ca(II),150 ppm Mg(II),and 50 ppb Pb(II).The excellent results of the TiO2-rGO sensor can be attributed to synergic effects between TiO2 and rGO,resulting from the presence of n-p heterojunctions and the formation of the TiO2 nanoparticles on rGO.
