Optimizing the Gas–Solid Photocatalytic Reactions for Air Purification

Abstract

The development of photocatalytic air purification technology is limited by the unsatisfactory performance and low suitability for real industrialization. In this Perspective, the strategy of optimizing the overall reaction processes to enhance photocatalytic performance is discussed. Also, the reaction mechanism and then tuning reaction kinetics are emphasized for guiding the rational design of photocatalysts. Further, we describe the development of humidity-independent, immobilized, and durable photocatalysts for multicomponent pollutants removal to meet the engineering requirements of practical applications. Finally, the outlook and challenges for photocatalytic air purification have been proposed to guide the future work.

Targeted H2O activation to manipulate the selective photocatalytic reduction of CO2to CH3OH over carbon nitride-supported cobalt sulfide

“…S15†), which is also often formed in the process of H 2 O activation. 21,23,59,60 In contrast, CN showed strong signals of ˙OH and ˙O 2 − , which may have been caused by the formation of holes (valence band: 2.07 eV) with strong oxidation capacity in CN (Fig. 4e and f).…”

Targeted NO Oxidation and Synchronous NO2 Inhibition via Oriented 1O2 Formation Based on Lewis Acid Site Adjustment

“…The ppb-level nitrogen oxides (NO x , x = 1, 2, the proportion of NO is about 95%) are an important precursor to participate in the formation of secondary organic aerosols and ozone, leading to current atmospheric environmental problems. − Over the past decades, substantial efforts have been made on searching purification strategies for trace NO; photocatalytic oxidation stands out from the crowd, holding the advantage of a more convenient, lower cost, and smaller environmental footprint. − Nevertheless, as an odd-electron molecule, NO exhibits excellent reactivity and thus owns various reaction pathways. , There is a sacrifice in environmental benefits when NO 2 emerges as an end-product, whose exposure is linked to serious respiratory illness, decreased lung function, and airway inflammation. , Considering the multiple reaction pathways of NO and the toxicity of NO 2 , an effective strategy of inhibiting the formation of NO 2 during photocatalytic NO oxidation should be well developed to guarantee better environmental significance. Proverbially, reactive oxygen species (ROS) dominate the performance of oxidation process. − In other words, a rational design of photocatalysts, aiming to achieve precise regulation of the ROS evolution process and thus oriented ROS formation, is the root of highly efficient photocatalytic NO oxidation with synchronous NO 2 inhibition.…”

C–Doping Induced Oxygen-Vacancy in WO3 Nanosheets for CO2 Activation and Photoreduction

“…With the excessive combustion of fossil fuels, the energy crisis and environmental pollution have become serious problems worldwide. − In this context, solar-driven CO 2 conversion into value-added fuels or feedstock has been identified as a sustainable and clean energy conversion technology to solve the aforementioned issues. − However, the conversion efficiencies of photoreduction CO 2 are far from satisfactory, because of the high thermodynamic stability of CO bonds and the limitation of charge kinetics (e.g., photoinduced generation of electron–hole pairs, charge separation and migration/transfer, and surface catalytic reaction). − Thus, in order to develop highly efficient catalysts for photocatalytic CO 2 reduction, the surface adsorption/activation of CO 2 and charge carrier kinetics should be considered simultaneously.…”