SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2023, Vol. 64 ›› Issue (12): 49-63.DOI: 10.1016/j.cjche.2023.06.014

• Full Length Article • 上一篇    下一篇

Enhanced photocatalytic activity of methylene blue using heterojunction Ag@TiO2 nanocomposite: Mechanistic and optimization study

Saptarshi Ghosh1, Kamalesh Sen2, Priyanka Debnath2, Arghadip Mondal2, Naba Kumar Mondal2   

  1. 1. Aerosol and Nanoparticle Technology Laboratory, Environmental Science and Engineering Department. Indian Institute of Technology Bombay, Mumbai 400076, India;
    2. Environmental Chemistry Laboratory, Department of Environmental Science, The University of Burdwan, W.B 713104, India
  • 收稿日期:2023-02-07 修回日期:2023-05-06 出版日期:2023-12-28 发布日期:2024-02-05
  • 通讯作者: Naba Kumar Mondal,E-mail:nkmondal@envsc.buruniv.ac.in
  • 基金资助:
    The authors would like to thank University of Burdwan was for instrumental and financial support from DST-FIST (SR/FST/ESI-141/2015, dt: 30.09.2019), Govt. of India and WBDST-BOOST (39/WBBDC/1p-2/2013, dt: 25.03.2015), Govt. of West Bengal.

Enhanced photocatalytic activity of methylene blue using heterojunction Ag@TiO2 nanocomposite: Mechanistic and optimization study

Saptarshi Ghosh1, Kamalesh Sen2, Priyanka Debnath2, Arghadip Mondal2, Naba Kumar Mondal2   

  1. 1. Aerosol and Nanoparticle Technology Laboratory, Environmental Science and Engineering Department. Indian Institute of Technology Bombay, Mumbai 400076, India;
    2. Environmental Chemistry Laboratory, Department of Environmental Science, The University of Burdwan, W.B 713104, India
  • Received:2023-02-07 Revised:2023-05-06 Online:2023-12-28 Published:2024-02-05
  • Contact: Naba Kumar Mondal,E-mail:nkmondal@envsc.buruniv.ac.in
  • Supported by:
    The authors would like to thank University of Burdwan was for instrumental and financial support from DST-FIST (SR/FST/ESI-141/2015, dt: 30.09.2019), Govt. of India and WBDST-BOOST (39/WBBDC/1p-2/2013, dt: 25.03.2015), Govt. of West Bengal.

摘要: The objective in this study is to investigate the adsorption-degradation of the methylene blue (MB) dye using a fabricated heterojunction Ag@TiO2 nanocomposite. The batch factors used in photo catalytic reactions were pH, UV-irradiation time, temperature, catalytic dosage, and concentration of MB. The results showed that 0.2×103 g·ml-1) of the catalytic dose caused the Ag@TiO2 adsorption to degrade by 96.67% with darks and UV exposure. Using the Langmuir-Hinshelwood model to determine the kinetic, the Ag@TiO2 displays a greater kinetic rate than TiO2 and silver nanoparticle (AgNPs). The photocatalytic degradation of MB, which is an endothermic reaction involving all catalysts, is shown by the thermodynamic parameter to have the positive value of enthalpy (ΔH°). The enthalpies observed were Ag@TiO2 (126.80 kJ·mol-1) < AgNPs (354.47 kJ·mol-1) < TiO2 (430.04 kJ·mol-1). Ascorbic acid (·OH scavenger), 2-propanol (·O2 scavenger), and ammonium oxalate (AO) (hole h+ scavenger) were employed to conduct the scavenger effects. The Ag@TiO2 demonstrated a reduction in MB degradation when combined with 2-propanol, and this clearly demonstrated that, in contrast to hydroxyl radicals (·OH) and hole (h+) scavengers, superoxide radical anion (·O2 scavenger) plays a significant role in MB degradation. Utilizing density functional theory (DFT) to elucidate the mechanism and B3LYP/6-311+G(d,p) level optimization, the degradation-adsorption process was explained. When the N-N, C-N or C-C bonds were severed, the Fukui faction was demonstrated for nucleophilic, electrophilic, and radical attack.

关键词: Heterojunction Ag@TiO2 nanocomposite, Methylene blue dye, Langmuir–Hinshelwood model, Scavenger, Density functional theoty

Abstract: The objective in this study is to investigate the adsorption-degradation of the methylene blue (MB) dye using a fabricated heterojunction Ag@TiO2 nanocomposite. The batch factors used in photo catalytic reactions were pH, UV-irradiation time, temperature, catalytic dosage, and concentration of MB. The results showed that 0.2×103 g·ml-1) of the catalytic dose caused the Ag@TiO2 adsorption to degrade by 96.67% with darks and UV exposure. Using the Langmuir-Hinshelwood model to determine the kinetic, the Ag@TiO2 displays a greater kinetic rate than TiO2 and silver nanoparticle (AgNPs). The photocatalytic degradation of MB, which is an endothermic reaction involving all catalysts, is shown by the thermodynamic parameter to have the positive value of enthalpy (ΔH°). The enthalpies observed were Ag@TiO2 (126.80 kJ·mol-1) < AgNPs (354.47 kJ·mol-1) < TiO2 (430.04 kJ·mol-1). Ascorbic acid (·OH scavenger), 2-propanol (·O2 scavenger), and ammonium oxalate (AO) (hole h+ scavenger) were employed to conduct the scavenger effects. The Ag@TiO2 demonstrated a reduction in MB degradation when combined with 2-propanol, and this clearly demonstrated that, in contrast to hydroxyl radicals (·OH) and hole (h+) scavengers, superoxide radical anion (·O2 scavenger) plays a significant role in MB degradation. Utilizing density functional theory (DFT) to elucidate the mechanism and B3LYP/6-311+G(d,p) level optimization, the degradation-adsorption process was explained. When the N-N, C-N or C-C bonds were severed, the Fukui faction was demonstrated for nucleophilic, electrophilic, and radical attack.

Key words: Heterojunction Ag@TiO2 nanocomposite, Methylene blue dye, Langmuir–Hinshelwood model, Scavenger, Density functional theoty