| Carbon materials with different morphologies,such as carbon spheres,carbon films and 3D carbon materials,have their unique properties and applications.However,simple and efficient synthesis methods and carbon precursors are the key to the preparation of carbon spheres,carbon films and three-dimensional carbon blocks.Therefore,we have established a new method of hydrothermal preparation of carbon spheres(CSs1 and CSs2),carbon films(CFs)and three-dimensional carbon blocks(3D-CBs).On this basis,their the morphology,structure and properties were studied,and the potential of CFs1 in corrosion resistance,CSs2 adsorption of dyes and the electrodes of 3D-CBs in capacitors were preliminarily discussed.The main results of this paper are as follows:Using vitamin C(VC)as carbon source,carbon sphere(CSs1),amorphous carbon film(CFs)and three-dimensional carbon block(3D-CBs)can be directly obtained by hydrothermal carbonization.The particle size of the CSs1 is 1-5μm.CSs1 was washed with ethanol and dried to obtain carbon spheres(CSs2)with narrow size distribution(1-1.5μm),high specific surface area(1222.9 m~2/g),porous structure(0-25 nm),rich oxygen-containing functional groups(-COOH,-OH,etc.),good conductivity,excellent optical and photoelectric properties.During hydrothermal process,CFs1 in the upper layer of the reaction system with slightly rough surface and abundant oxygen-containing functional groups is formed by the aggregation of nano-carbon spheres(17-50 nm),which has good electrical conductivity and exhibits certain photoelectric properties.It can be well attached to different substrate substrates without any adhesive,and has the function of blocking electron transfer.3D-CBs is a kind of three-dimensional structure with a height of 2 mm formed by the accumulation of smooth carbon spheres,which vary in size and have diameters between 0.3-4.5μm.It has a good absorption and a narrow direct band gap(1.46 e V)in the near-infrared region,and a large number of carboxyl and hydroxyl groups on the surface.This method selects a single precursor to prepare three kinds of carbon materials with multi-purpose morphology by hydrothermal reaction,which has the advantages of simple operation and environmental friendliness,and provides a reference for the preparation of carbon materials with different morphologies.Based on the continuous integrity,good biocompatibility,electron transfer hindrance and high conductivity of CFs,we studied its corrosion resistance on copper.The results of cyclic voltammetry,open circuit potential,Tafel curve and electrochemical impedance spectroscopy show that the film has anti-corrosion effect.Compared with quantum dots and graphene solution,CFs1 has the best corrosion resistance.At the same time,it also has the function of anti-corrosion under long-time immersion.In addition,when the applied voltage is 0.3 V,the CFs1 has a relatively stable and weak photoelectric response.Based on the high specific surface area and porosity of porous carbon microsphere(CSs2),it was used to study the adsorption of cationic dyes.Firstly,the adsorption conditions(light source,amount of adsorbent,p H value,dye volume,initial concentration and temperature)are optimized to maximize the removal rate and adsorption amount in a short time.The results showed that 50 m L 10 mg/g MB could be completely adsorbed by 20 mg CSs2 at p H=6.0,180min.And the removal rate closed to 100%and the adsorption capacity was 23.9 mg/g.Moreover,it can be reused 11 times and still has good adsorption performance.CSs2 is a kind of adsorbent with good development potential.The three-dimensional(3D)carbon materials can be directly used as capacitor electrodes,which is a kind of capacitor electrode material with good development potential,and can provide a simple and effective method for energy conversion and storage applications. |
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