Rising levels of nitrate and nitrogen in water bodies pose a potential threat to aquatic ecosystems and human health. Therefore, it is urgent to solve the problem of excessive nitrate in water bodies. Fe(NO₃)₃·9H₂O, Co(NO₃)₂·6H₂O, reed biochar, NH₃·H₂O was used as raw material, and co?precipitation method was used to load cobalt?iron layered bimetals onto reed biochar to prepare Co/Fe?LDH@BC for adsorption of excess nitrate nitrogen in water. The experimental results showed that Co/Fe?LDH@BC could effectively adsorb nitrate nitrogen in water, and its adsorption capacity was 88.52 mg/g. The adsorption kinetic model conforms to the pseudo?second?order kinetic model, and the isotherm conforms to the Langmuir isotherm model, indicating that the adsorption reaction is spontaneous and endothermic, which mainly involves four reaction mechanisms: ion exchange, ligand exchange, electrostatic attraction and hydrogen bonding. In addition, Co/Fe?LDH@BC has a strong affinity for nitrate nitrogen in most water bodies where coexisting anions are present, making it suitable for practical applications.

While fossil energy is being exhausted day by day,and the problem of environmental pollution needs to be solved urgently.However,the social demand for energy is growing,so the development of green energy has received extensive attention from many scientific researchers.As an efficient energy conversion device,fuel cell has many advantages such as high efficiency, high performance and environmental friendliness.In the choice of fuel cell catalyst,Pt?based catalysts are the preferred materials because of their unique catalytic properties,but their high preparation cost and unstable catalytic properties have hindered the commercialisation of Pt?based catalysts.The working principle of Pt?based catalysts for cathode oxygen reduction reaction of proton exchange membrane fuel cells and the influencing mechanism of catalyst activity are briefly introduced.The research direction of Pt?based catalysts is summarized.Finally,the development direction of future research is prospected.

Common wicker,the raw material of biochar,was treated by hexadecyltrimethylammonium chloride (CTMAC) for cationic surface activation,and then it was mixed with zero?valent iron and sodium alginate to prepare zero?valent iron/cationic surfactant/biochar (Fe⁰?MBC) gel microspheres, and their ability to adsorb Cr(VI) in water was discussed.The structure and properties of Fe⁰?MBC gel microspheres were studied by means of XRF,FTIR,XRD and Zeta potential.Upon the analysis of the effects of the reaction time,temperature and pH value on adsorption,the adsorption mechanism was preliminarily discussed on the basis of adsorption kinetics and the isotherm model.The results indicate that the adsorption effect of Fe⁰?MBC gel microspheres on Cr(VI) is highly fitted with that of pseudo?first?order kinetics and the Langmuir isothermal adsorption model. The removal rates of Cr(VI) by CTMAC?activated biochar loaded with 5% zero?valent iron and CTMAC?activated biochar loaded with 10% zero?valent iron can reach 89% and 97% (initial Cr concentration of 100 mg/L) at 2 h, respectively, and the maximum saturated adsorption capacities are 33.777 9 mg/g and 42.562 0 mg/g, respectively.The experimental results reveal that Fe⁰?MBC gel microspheres, as a low?cost and high?efficiency environmental functional material, have good application prospects for the removal of Cr(VI) in wastewater.