Vertically Heteroatom Doped Single-walled Carbon Nanotubes With Plated Metals As High Performance Materials For Electrochemical Study

Organophosphorus pesticides?OPs?are widely used in agricultural production because of their high toxicity for the pests.However,certain OPs and their degradation products in food and drinking water can cause harm to human health even at low levels of exposure.Thus,it is important to develop efficient and simple methods to detect OPs.The acetylcholinesterase?ACh E?is often used in the preparation of electrochemical biosensors for the detection of OPs because of its specificity to OPs.An ACh E biosensor was constructed based on gold nanoparticles?Au NPs?using electroless plating on vertically nitrogen-doped single-walled carbon nanotubes?VNSWCNTs?for detecting organophosphorus pesticides?OPs?.ACh E was immobilized on Au NPs via Au-S bonding,and VNSWCNTs were produced by spontaneous chemical adsorption of NSWCNTs on gold electrode,also via Au-S bonding.This modified electrode exhibited excellent electron transfer capacity due to the synergy between Au NPs and VNSWCNTs.The developed biosensor showed good linear relations at concentrations of 10^-9-10^-14M,and the detection limits were 1.15×10^-14M for methyl parathion,5.9×10^-15M for malathion,and 5.87×10^-15M for chlorpyrifos,respectively.After 28 days of storage,the ACh E biosensor still maintained 95%of the initial current.The recovery range of the biosensor in the real samples was 95%?105%,and the relative standard deviation?RSD?was 3.74%,indicating that the biosensor had a good application in the real sample.Therefore,the ACh E biosensor prepared in this experiment can be used as a sensitive device for OPs analysis.These results suggest that this biosensor has good application prospects and can function as a sensitive device in OPs analysis.Moreover,a highly efficient and cost-efficient catalyst for overall water splitting was consisted of Fe Co Ni P alloy nanoparticles integrated on vertically aligned phosphorus-doped single-walled carbon nanotubes?VPSWCNTs?.The catalyst exhibited excellent catalytic performance in 1.0 M KOH for hydrogen evolution reaction?HER?and oxygen evolution reaction?OER?with the current density of 10 m A cm^-2.The overpotential of HER was 147 m V,which was closed to Pt/C 145m V,and the Tafel slope was 64 m V dec^-1better than the Pt/C(177m V dec^-1).The performance of catalyst in OER(overpotential of 280 m V and Tafel slope of 43 m V dec^-1)was lower than Ir O₂(overpotential of 310 m V,Tafel slope of 57 m V dec^-1).Fe Co Ni P/VPSWCNTs/Au exhibited good stability and activity for at least 10 h,and the potential of the catalyst changed slightly,indicated that the prepared electrocatalyst had good durability under alkaline conditions.These results indicate that catalyst can be used as cost-effective and earth-abundant non-noble-metal efficient catalyst for overall water splitting.