| Controlling the emission of nitrogen oxides in industrial flue gas has received widespread attention.The current denitration technology is mainly suitable for high temperature industrial flue gas,and the denitration effect of low temperature industrial flue gas is not ideal.For the purpose of improving the process and saving costs,it is necessary to develop a denitration process suitable for low-temperature flue gas.Photothermal synergistic catalysis,combining photocatalysis and thermal catalysis to produce a synergistic effect,the catalyst can be activated in a low-temperature industrial flue gas environment.Relevant studies have shown that photothermal synergistic catalysis can effectively improve the catalytic effect compared with photocatalysis,but its ability to treat high concentrations of nitrogen oxides in industrial flue gas is still limited.It has certain practical significance to combine photothermal synergy with hydrogen peroxide to improve the denitration effect.The specific research contents are as follows:In this paper,g-C3N4 nanosheets were firstly made by thermal peel,and different forms of Co3O4 were loaded on g-C3N4 nanosheets by hydrothermal and solvothermal methods.Then,the composites were characterized by SEM,TEM,XRD,FT-IR,XPS,BET,DRS,EPR radical test and electrochemical test,etc.The morphology,chemical composition,energy band structure,the flow separation efficiency,photogenerated load of the material and other properties were analyzed.Afterwards,the photocatalytic and photothermal synergistic catalysis of Co3O4/g-C3N4 composites with different morphologies were further explored for the removal of NO by hydrogen peroxide.In the experiment of hydrogen peroxide-assisted photocatalytic degradation of NO,Co3O4 nanotubes/g-C3N4 nanosheets showed better catalytic performance than Co3O4 nanosheets/g-C3N4 nanosheets and Co3O4nanospheres/g-C3N4 nanosheets,the Co3O4 nanotube/g-C3N4 nanosheet material with a molar ratio of 1:3 has the highest degradation rate of 82.1%.Co3O4 nanotubes/g-C3N4nanosheets exhibited better catalysis than Co3O4 nanosheets/g-C3N4 nanosheets and Co3O4 nanospheres/g-C3N4 nanosheets in the photothermal synergistic degradation of NO assisted by hydrogen peroxide performance,the Co3O4 nanotube/g-C3N4 nanosheet material with a molar ratio of 1:1 has the highest degradation rate,with a degradation rate of 99.3%at 110℃.According to the above characterization and performance tests,compared with photocatalysis and thermal catalysis,photothermal synergistic catalysis could produce a synergistic effect to achieve better catalytic effect.The experiment also explored the effect of reaction conditions on catalysis.The experimental results showed that the optimal reaction temperature of the catalyst was 110°C.Changes in reaction conditions such as hydrogen peroxide concentration,NO concentration,and flow rate had a significant impact on the catalytic efficiency.The change of oxygen concentration had no obvious effect on the catalytic efficiency of the catalyst.According to the characterization and performance test,the possible mechanism of Co3O4/g-C3N4composites hydrogen peroxide-assisted photothermal synergistic degradation of NO was proposed.The combined effect of photocatalysis and thermocatalysis promoted the improvement of catalytic efficiency. |
