Study On Preparation And Properties Of Nickel Hydroxide Environmental Composites

Energy problems and environmental pollution are the bottlenecks restricting economic development.Green,new energy such as solar energy,wind energy and geothermal energy generally have disadvantages such as uneven distribution,influenced by external factors such as weather and time.Therefore,the development of energy storage devices is the key to the development and utilization of clean energy.As a commonly used energy storage device,lead-acid batteries,while solving the problem of green new energy storage,have brought irreversible pollution to the environment.The supercapacitor has become a green environmental protection device because it does not use heavy metals and other harmful chemicals.As the core component of supercapacitors,designing electrode materials with excellent performance has become the focus of scientific researchers.Composite functional materials take advantage of the synergy between different substances and can exhibit excellent performance in different applications.Therefore,it is of far-reaching significance to develop new environmental composite materials that have both excellent electrochemical properties and can be used to treat pollutants.Nickel hydroxide has a higher theoretical specific capacitance,has the advantages of adsorption,easy preparation and low price and the disadvantage of poor conductivity.However,phenolic resin(RF)has stable mechanical properties and excellent electrical conductivity.The synthesis strategy of "strengthening the shortcomings" can be adopted,and it is expected to develop new environmental composites with both better electrochemical performance and higher adsorption.Therefore,on the basis of the synthesis of spherical Ni(OH)2,this study designed two nickel hydroxide environmental composite materials-Ni(OH)2@RF and RF/Ni(OH)2,And through the controllable preparation of the two environmental composite materials,the electrochemical and adsorption properties were discussed.The main research contents and results of this paper include:(1)Using the surfactant cetyltrimethylammonium bromide(CTAB)as a modifier,the RF layer was successfully wrapped on the outer surface of Ni(OH)2,and the Ni(OH)2@RF environment composite material was obtained;Then by controlling the amount of RF precursors,the controllable preparation of Ni(OH)2@RF was achieved;at the same time,the influence of RF wall thickness on the electrochemical performance of environmental composite materials was investigated.Electrochemical performance studies show that the optimized Ni(OH)2@RF had a specific capacitance value of 672 F/g when the current density was 5 A/g,and when the current density was 10 A/g,the specific capacitance was 502 F/g,a decrease of 25.3%;after 1000 cycles of testing the specific capacitance decreased from 672 F/g to 609 F/g,the capacity retention rate was 90.7%.Compared with nickel hydroxide,the specific capacitance and cycle stability of Ni(OH)2@RF environmental composites had been improved to a certain extent.(2)The RF/Ni(OH)2 environment composite material was successfully prepared by one-step hydrothermal method.The effects of RF addition,volume of Ni(OH)2 reaction solution and reaction time on the morphology and performance of RF/Ni(OH)2 were also investigated.The results show that the particle size of the RF/Ni(OH)2 decreases first and then stabilizes with the increase of RF addition,and with the increase of the volume of Ni(OH)2 reaction solution,it firstly increases and then tends to be stable.The electrochemical performance study shows that the optimized RF/Ni(OH)2 possessed a specific capacitance value of 1262 F/g when the current density was 5 A/g,and when the current density was 10 A/g,the ratio The capacitance was 1053 F/g,a decrease of 16.6%;after 1000 cycles of testing,the specific capacitance decreases from 1262 F/g to 1171 F/g the capacity retention rate was 92.8%.Compared with nickel hydroxide and Ni(OH)2@RF,the specific capacitance and cycle stability of RF/Ni(OH)2 had been greatly improved.Through the research on the AC impedance of the three materials,it is found that the RF/Ni(OH)2 had the lowest resistance,and thus had excellent electrochemical performance,and is an ideal environmental composite.(3)Taking Congo Red as the target pollutant,the adsorption capacities of the three adsorbents from small to large were:Ni(OH)2@RF<Ni(OH)2<RF/Ni(OH)2.The kinetic study of the adsorption of Congo red on the three materials shows that the adsorption of Congo by the three materials follows the second-order kinetic model.Among them,the maximum adsorption amount(170 mg/g)and initial adsorption rate of RF/Ni(OH)2 was the largest,which results in its good adsorption performance for Congo red.The adsorption isotherm of RF/Ni(OH)2 for Congo red showed that the Langmuir adsorption model can better describe the process of RF/Ni(OH)2 for Congo red.