Preparation And Electrochemical Performance Of Phenolic Resin Derived Carbon-based Composite

As an excellent carbon material,phenolic resin derived carbon is used in many fields.However,the low preparation temperature was required to prevent phase change of the enhanced phase when phenolic resin carbon was compounded with diamond or other enhanced phase.In this paper,phenolic resin carbon(C_PR),phenolic resin carbon/diamond(C_PR/D)and phenolic resin carbon/boron carbide(C_PR/B₄C)composite materials were prepared by low temperature carbonization,which were applied to the fields of electrochemical analysis and electrochemical splitting of water/seawater.Using phenolic resin as the precursor,the compact C_PR with snowflake shape homogeneous carbon particles were prepared by 800?.C_PR/D was obtained after diamond particles added to phenolic resin,which diamond particles were uniformly distributed on the C_PR matrix.Adding boron carbide to the phenolic resin,C_PR/B₄C was prepared using the high strength and gettering properties of boron carbide,which can reduce the pores of the phenolic resin-derived carbon and increase the strength of the material(65.5 MPa).C_PR and C_PR/D were used to electrochemical analysis of dopamine(DA)and uric acid(UA).Both of them can clearly distinguish the oxidation peaks of DA and UA,which the separation potential of the oxidation peaks of DA and UA reached 260 m V(C_PR)and300 m V(C_PR/D),and electrochemical analysis of DA and UA can be performed simultaneously.The insulating diamond particles in C_PR/D divide the C_PR into micron-sized areas,which array-like structure was suitable for electrochemical analysis.The limit detection of C_PR/D decreased from 0.401?M(DA)and 2.800?M(UA)of C_PR to 0.334?M(DA)and 0.455?M(UA),respectively.Nickel foam(NF)was impregnated in ethanol solution of phenolic resin containing with B₄C.Then it was annealed at 800?to prepare C_PR/B₄C composite coating on the NF(NF-C_PR-B₄C).During the carbonization process of phenolic resin,B₄C and NF form crystalline Ni₂B with excellent OER catalytic activity.Meanwhile,the C_PR coating can effectively resist the corrosion of Cl^-in seawater.The catalytic performance of NF-C_PR-B₄C with different ratios of phenolic resin and boron carbide was studied.Among them,NF-0.1C_PR-0.5B₄C exhibited an excellent OER catalytic activity with low overpotentials of240 m V to achieve 100 m A cm^-2 and a low Tafel slope(41 m V dec^-1)in 1 M KOH.In addition,the NF-0.1C_PR-0.5B₄C also possessed low overpotentials of 270 m V to achieve100 m A cm^-2 in alkaline seawater(1 M KOH+seawater).Meanwhile,NF-0.1C_PR-0.5B₄C can still maintain excellent OER stability(decay less than 15%)in alkaline seawater at100 m A cm^-2 for 24 h,and good corrosion resistance in natural seawater(E_corr=-0.49 V,I_corr=125.9 u A cm^-2).