Visible-Light-Active Plasmonic Ag–SrTiO₃ Nanocomposites for the Degradation of NO in Air with High Selectivity

Abstract

Harnessing inexhaustible solar energy for photocatalytic disposal of nitrogen oxides is of great significance nowadays. In this study, Ag-SrTiO3 nanocomposites (Ag-STO) were synthesized via one-pot solvothermal method for the first time. The deposition of Ag nanoparticles incurs a broad plasmonic resonance absorption in the visible light range, resulting in enhanced visible light driven activity on NO removal in comparison with pristine SrTiO3. The Ag loading amount has a significant influence on light absorption properties of Ag-STO, which further affects the photocatalytic efficiency. It was shown that 0.5% Ag loading onto SrTiO3 (in mass ratio) could remove 30% of NO in a single reaction path under visible light irradiation, which is twice higher than that achieved on pristine SrTiO3. Most importantly, the generation of harmful intermediate (NO2) is largely inhibited over SrTiO3 and Ag-STO nanocomposites, which can be ascribed to the basic surface property of strontium sites. As identified by electron spin resonance (ESR) spectra,·O2(-) and ·OH radicals are the major reactive species for NO oxidation. Essentially speaking, the abundance of reactive oxygen radicals produced over Ag-STO nanocomposites are responsible for the improved photocatalytic activity. This work provides a facile and controllable route to fabricate plasmonic Ag-SrTiO3 nanocomposite photocatalyst featuring high visible light activity and selectivity for NO abatement.

Fabrication of Bi2O2CO3/g-C3N4 heterojunctions for efficiently photocatalytic NO in air removal: In-situ self-sacrificial synthesis, characterizations and mechanistic study

“…Single semiconductor cannot fulfill the above harsh terms simultaneously. Hence, numerous strategies, such as element doping [15], noble deposition [16], and surface modification [17], have been developed to improve the photocatalytic activities of catalysts in the past decade.…”

High Selectivity of Visible-Light-Driven La-doped TiO2 Photocatalysts for NO Removal

“…The removal ratio of NO at any onetime was noted as (1 -C/C 0 ), where C is the NO concentration of the outlet at any one time, and C 0 is the initial concentration of NO, ppb. The selectivity of NO 2 over different photocatalysts was calculated by the following equation (Zhang et al, 2016):…”

“…However, these technologies inevitably require the use of noble metals, high temperatures and high costs for the high-concentration NO x treatment that is part of the process. Photocatalysis, which mainly refers to heterogeneous catalysis, offers an innovative and promising approach to reduce NO x at the part-per-billion (ppb) level (Wang et al, 2016c;Zhang et al, 2016).…”

Impact of Annealing Thin Films In(OH)xSy Growth By Solution Technique

“…According to the research done on the electronic engineering of solid-state DSSC, passivation of interface recombination can be of fundamental importance in systems like ETAsolar cells [6] and In(OH)xSy is one of the proposed buffer layers [18]. The In(OH)xSy layers have been deposited by a wet CBD and has proved to be a good buffer for TiO2 solar cells with its band gap energy varying in the range 2.4-3.4 eV depending on stoichiometry of In(OH)xSy [14,24]. The dark I-V characteristics obtained confirm that In(OH)xSy coating was good and free of pin holes that can lead to shorting of the current.…”

“…The dark I-V characteristics obtained confirm that In(OH)xSy coating was good and free of pin holes that can lead to shorting of the current. Consequently, after annealing the films at 300 ℃ for 30 minutes, the material changes from amorphous state to crystalline state and also becomes slightly rich in In2S3 content [24,20]. The buffer film can minimize the electron-hole pair recombination and the capability of the n-type semiconductor when infiltrated with the p-type absorber [25].…”