Preparation Of Bismuth Sodium Molybdate-based Composite Pressed-tablet Electrodes And Photoelectric Synergistic Catalytic Degradation Of Antibiotics

The rapid progress of human society,the rapid growth of population and the rapid development of modern industry,people's living standards continue to improve at the same time,bringing a large number of environmental pollution and ecological damage and other problems that limit the continuous development of human beings.In recent years,organic pollution of water bodies represented by antibiotic pollution has become one of the significant environmental problems,obviously the traditional wastewater treatment technology has been far from meeting the treatment of such wastewater,so the development of more efficient treatment methods has become an urgent need of the moment.At present,the advanced oxidation technology of photocatalytic technology has become one of the favored technologies to solve the difficult to degrade organic pollution wastewater,this technology can be generated through the strong oxidizing effect of hydroxyl radicals(·OH),superoxide radicals(·O₂^-)and other free radicals that can be present in the water,in order to achieve high-speed,efficient oxidative degradation of antibiotic organic pollutants,for the traditional additive powder photocatalytic For traditional powder photocatalytic materials,there are many obstacles to their development and application,such as the difficulty of recycling,poor absorption and utilization of visible light energy,serious compounding of photogenerated carriers,and low efficiency in the treatment of large organic pollutants.In this dissertation,we designed a NaBi(MoO₄)₂-based pressed-sheet electrode photocatalytic(PEC)system and carried out research on the preparation of novel and efficient NaBi(MoO₄)₂-based pressed-sheet electrode materials,visible light response expansion,and photocatalytic(PEC)degradation of antibiotics and other environmental purification aspects to achieve efficient treatment of organic pollutants.The paper firstly synthesizes pure NaBi(MoO₄)₂pressed-sheet electrode materials by one-step hydrothermal method through rare-earth ion doping,and similarly synthesizes NaBi(MoO₄)₂-based materials doped with different ratios of yttrium ions by one-step hydrothermal method,and characterizes them by crystallography,morphology,spectral-energy spectroscopy,and electrochemical tests,while they are then combined with pure NaBi(MoO₄)₂pressed-sheet electrodes were compared with pure NaBi(MoO₄)₂pressed sheet electrodes for environmental cleanup performance under the action of PEC.It was found that the 1.5%Y-NaBi(MoO₄)₂pressed-chip electrode with a molar ratio of 1.5%Y doping showed the best environmental cleanup performance,in which 1.5%Y-NaBi(MoO₄)₂degraded tetracycline hydrochloride at a concentration of 10 mg/L with a removal efficiency of100%in 70 min,compared with the pure NaBi(MoO₄)₂pressed-chip electrode.The crystallographic and morphological characterization shows that the electrode material of 1.5%Y-NaBi(MoO₄)₂pressed sheet electrode retains the basic morphological features of NaBi(MoO₄)₂base material in SEM and TEM,while Y-doped diffraction peaks and Y-doped lattice stripes are observed in XRD patterns and HRTEM.The1.5%Y-NaBi(MoO₄)₂electrode material also exhibits more optimized optoelectronic properties than NaBi(MoO₄)₂electrode material and other Y-doped NaBi(MoO₄)₂electrode materials in both spectroscopy/energy spectroscopy and electrochemical characterization.After the experimental tests confirmed that the 1.5%Y-NaBi(MoO₄)₂pressed electrode with 1.5%Y doping showed the best environmental cleanup performance,the 1.5%Y-NaBi(MoO₄)₂materials with different ratios of Mo S₂QDs were compounded by a two-step hydrothermal synthesis method and then crystallographically,morphologically,spectroscopically,and electrochemically characterized as well.The environmental cleanup performance was compared with that of 1.5%Y-Bi₂MO₆pressed sheet electrode under the action of PEC.It was found that the 1.5%Y-NaBi(MoO₄)₂pressed sheet electrode with 40%Mo S₂QDs by mass had the best environmental cleanup performance,in which 40%Mo S₂QDs/1.5Y-NaBi(MoO₄)₂degraded tetracycline hydrochloride at a concentration of 25mg/L with a removal efficiency of 100%in 50 min.The crystallographic and morphological characterization shows that the electrode material of 40%Mo S₂QDs/1.5Y-NaBi(MoO₄)₂pressed sheet electrode retains the basic morphological features of NaBi(MoO₄)₂base material 2D sheet material and Mo S₂QDs zero-dimensional point material in SEM and TEM,while the XRD patterns and HRTEM observe The diffraction peaks of Mo S₂QDs composite and the lattice stripes of Mo S₂QDs composite with NaBi(MoO₄)₂two-dimensional sheet material formed0D/2D type heterojunction.Meanwhile,40%Mo S₂QDs/1.5%Y-NaBi(MoO₄)₂exhibit more optimized optoelectronic properties compared with other 1.5Y-NaBi(MoO₄)₂and other ratios of Mo S₂composite NaBi(MoO₄)₂in both spectroscopy/energy spectroscopy and photoelectrochemical characterization.The experiments were concluded with first principles theoretical calculations for three electrode materials,NaBi(MoO₄)₂,Y-NaBi(MoO₄)₂,and Mo S₂QDs/Y-NaBi(MoO₄)₂.The calculations include energy band structure,electronic density of states,PDOS,TDOS,and Work Function.The theoretical settlement results show that the experimental tests of all types of electrode materials are consistent with the theoretical calculations,and the work function calculations show that the mechanism of hole-dominated action in the PEC reaction is enhanced in MoS₂QDs/Y-NaBi(MoO₄)₂.