No abstract

As an alternative to the investigation of photocatalysts, it is a potential approach to enhance the photocatalytic performance of the novel photocatalytic reactor by optimizing its geometric structure and reaction conditions. In this work, ve different honeycomb photocatalytic reactors with a de ector and a porous air ow distribution plate were designed and a numerical simulation was performed based on computational uid dynamics (CFD). The simulation results showed that a huge vortex appeared near the entrance of the original model and the velocity distribution inside the reactor was non-uniform, whereas these shortcomings could be effectively overcome when using the 45° de ector model (S-4) compared to the other models. Compared to S-1, the photocatalytic conversion rate of formaldehyde for S-4 was boosted by 7.29% at a ow velocity of 0.04 m s −1 . In addition, it was found that the photocatalytic conversion rate of formaldehyde increased from 55.45-94.73% when the velocity decreased from 0.04 to 0.01 m s −1 , and the photocatalytic removal rate of formaldehyde decreased from 94.73-70.05% as the relative humidity varied from 20-70%. Furthermore, when the irradiance increased from 45 to 265 mW cm −2 , the photocatalytic conversion rate of formaldehyde improved by 10.78%. Overall, this work contributes to the design of the novel honeycomb reactor to acquire the optimized construction of the photocatalytic reactor.

In this study, Pt-M/WO3 (M = Cu, Co, and Ni) thin films are effectively synthesized by preparing homogeneous precursor sols, spin-coating, toluene-etching, and calcination. Furthermore, the microstructural, chemical, and electrochemical properties of the WO3, Pt-Cu/WO3, Pt-Co/WO3, and Pt-Ni/WO3 thin films are also systematically compared. The results demonstrate that when compared to the WO3 thin film, the photocatalytic capability for methylene blue (MB) solution degradation is greatly increased in the Pt-M/WO3 thin films. Transfer routes for photogenerated charges and an improved photocatalytic process are suggested based on the experimental results. Due to the large difference in the work function (Φ) between the bimetallic alloy Pt-M and WO3, a bending of the energy bands at the Pt-M/WO3 interface is presented. Furthermore, the introduction of transition metals such as Cu, Co, or Ni modifies the electronic structure of Pt-M/WO3 thin films, facilitating the separation and migration of electrons and holes. Specifically, the photogenerated electrons migrate from the CB of WO3 to Pt-Co or Pt-Ni nanoparticles in the samples of Pt-Co/WO3 or Pt-Ni/WO3 thin films, while the hot electrons from the localized surface plasmon resonance (LSPR) effect of Cu could transfer to the conduction band (CB) of WO3 and other electrons generated from the photoexcitation of the WO3 semiconductor itself in the sample of the Pt-Cu/WO3 thin film. In summary, this work proposes a unique strategy for creating electron regulation in Pt-M decorated WO3 thin films for photocatalytic application.

As an alternative to the investigation of photocatalysts, it is a potential approach to enhance the photocatalytic performance of the novel photocatalytic reactor by optimizing its geometric structure and reaction conditions. In this work, five different honeycomb photocatalytic reactors with a deflector and a porous airflow distribution plate were designed and a numerical simulation was performed based on computational fluid dynamics (CFD). The simulation results showed that a huge vortex appeared near the entrance of the original model and the velocity distribution inside the reactor was non-uniform, whereas these shortcomings could be effectively overcome when using the 45° deflector model (S-4) compared to the other models. Compared to S-1, the photocatalytic conversion rate of formaldehyde for S-4 was boosted by 7.29% at a flow velocity of 0.04 m s−1. In addition, it was found that the photocatalytic conversion rate of formaldehyde increased from 55.45–94.73% when the velocity decreased from 0.04 to 0.01 m s−1, and the photocatalytic removal rate of formaldehyde decreased from 94.73–70.05% as the relative humidity varied from 20–70%. Furthermore, when the irradiance increased from 45 to 265 mW cm−2, the photocatalytic conversion rate of formaldehyde improved by 10.78%. Overall, this work contributes to the design of the novel honeycomb reactor to acquire the optimized construction of the photocatalytic reactor.