Preparation Of SiC Material From Solar Cells And Its Application

With the widespread use of solar energy,a large number of solar cells are discarded after their lifespan has expired.If the waste solar cells are not disposed of properly,they will have an adverse impact on the environment.Therefore,it is imperative to recycle waste solar cells.This article focuses on the technology of recycling silicon in waste solar cells.A silicon solar material is prepared by using a waste solar cell as a silicon source,activated carbon,and graphite extracted from the waste battery as a carbon source by a carbothermal synthesis method.The effect of preparation conditions on the performance of silicon carbide was studied,and the materials were analyzed by XRD,SEM,XPS;the synthesized silicon carbide was used for electrocatalytic hydrogen evolution,and the catalytic performance of silicon carbide was studied by LSV,Tafel slope and impedance test analysis.1)Using AgNO₃,Fe₂O₃ and AgNO₃and Fe₂O₃ composite catalysts,activated carbon as the carbon source,and silicon carbide powders were obtained by a carbothermal synthesis method.The XRD results showed thatβ-Si C,AgNO₃ and Fe₂O₃ can be used to prepare Si C materials catalyzed by the three catalytic systems.Compared with pure Si C,the catalytic performance of electrolyzed water has been improved,but the HER overpotential has not decreased significantly.For AgNO₃ and Fe₂O₃ composite catalyst system,at 1500℃,the carbon-silicon molar ratio is 3,and the Si C material prepared under the conditions of adding3%Fe₂O₃ and 3%AgNO₃ has a fiber rod-like whisker structure with a diameter of about 50nm.At 25℃,the electrocatalytic HER study in 0.5 M H₂SO₄ solution found that the overpotential reached 82 m V at a current density of 10 m A cm^-2,which is 2.9 times the commercial Ir O₂ overpotential(η₁₀=240).At the same time,the Tafel slope is 55.2 m V dec^-1.And after long-time cyclic scanning,the overpotential did not increase significantly,and the catalytic electrode had good stability.2)When graphite is used as the carbon source,similar to activated carbon,Si C materials prepared by AgNO₃,Fe₂O₃,AgNO₃ and Fe₂O₃ composite catalysis are allβ-Si C,and Si C materials prepared by AgNO₃ and Fe₂O₃ composite catalysis have better HER electrocatalytic performance than AgNO₃ and Fe₂O₃.Catalytically prepared Si C materials.At a temperature of 1500℃,the molar ratio of carbon to silicon is 2,and under the conditions of 3%AgNO₃and 3%Fe₂O₃,the Si C has the highest crystallinity and exhibits a fibrous structure.At 25℃,the electrocatalytic HER study in 0.5 M H₂SO₄ solution found that the overpotential reached64 m V at a current density of 10 m A cm^-2,which is 3.75 times that of the commercial Ir O₂overpotential(η₁₀=240).The Tafel slope is 53.9 m V dec^-1.Under a constant current of 10 m A cm^-2,the voltage does not change significantly after 500 turns of scanning,and the catalytic click has good stability.3)Graphite paper is used as a support to synthesize high-crystallinity Si C materials;the linear scanning voltammetry curve of Si C is tested under acidic conditions,and it is found that the overpotential reaches 75 m V at a current density of 10 m A cm^-2,and can Stable in current.After a long time current sweep,the overpotential remains almost stable.