CsPbBr₃ Perovskite Nanocrystal: A Robust Photocatalyst for Realizing NO Abatement

Abstract

Photocatalysis is a promising method for removing atmospheric NO but suffers from unsatisfactory removal efficiency and selectivity. Inorganic lead halide perovskites (LHPs) have been intensely investigated in the field of solar cells as new wonder materials. The intrinsic merits of LHPs provide additional opportunities for their use in fields beyond photovoltaics. Herein, for the first time, we extend the application of the low-cost lead inorganic CsPbBr 3 perovskite to high-performance photocatalytic elimination of NO under visible-light irradiation. The CsPbBr 3 nanocrystals (NCs) with an edge size of ca. 12 nm can reach a high NO removal activity (50.6%) under a gas hourly space velocity (GHSV) of 1,800,000 mL h −1 g −1 and obtain high selectivity (89.0%) for the formation of ionic species instead of more toxic NO 2 . A significant improvement for NO removal over the state-of-the-art photocatalysts with an outstanding long-term stability of up to 15 h is demonstrated. The excellent performance can be ascribed to the efficient charge separation and transfer and the visiblelight-harvesting ability of CsPbBr 3 NCs. These findings open a new avenue for the use of the low-cost, easy-to-process, highly efficient, and air-tolerant CsPbBr 3 perovskites toward air pollution remediation.

Photochemical Transformation Pathways of Nitrates from Photocatalytic NOx Oxidation: Implications for Controlling Secondary Pollutants

“…In atmospheric chemistry, photocatalysis is a non-negligible initiator for Earth’s transmutation of elements, due to the ubiquitous photocatalytic components in our daily life, including various fine particles of airborne particulate matter, windblown mineral dust, building exteriors, and road bricks. − In particular, the photocatalytic transformation of atmospheric trace species (NOx) has direct environmental implications under solar irradiation, as the elimination of NOx could alleviate pollution and protect human health. − Investigations of efficient photocatalytic NOx oxidation are emerging. − The final product obtained from photocatalytic NO oxidation is generally regarded as nitrates (NO 3 – ). − However, photogenerated radicals exhibit robust oxidation or reduction capacity for the species on the photocatalyst surface. − Additionally, there is insufficient experimental evidence to demonstrate that surface NO 3 – could exhibit high chemical stability during photocatalysis. Hence, it is rather doubtful whether the surface NO 3 – is stable during the sustained photocatalytic NO purification reaction.…”

Advances and challenges of photocatalytic technology for air purification

“…Among various air pollutants, NO x is mainly composed of nitric oxide (NO) and nitrogen dioxide (NO 2 ). In the atmospheric environment, NO is usually in low concentrations but extremely hazardous and can lead to acid rain when it comes in contact with air [32]. Although NO itself is not active, it can be easily oxidized by O 2 in the air to form NO 2 , which is a kind of highly corrosive and toxic gas.…”

Manipulating Excitonic Effects in Layered Bismuth Oxyhalides for Photocatalysis

“…The expansion of the world’s population and unrestrained industrial growth in the past few decades have escalated the consumption of fossil fuels (coal, petroleum, natural gas), as well as the unabated release of greenhouse gas (CO 2 ). − According to a report from Earth System Research Laboratories, the CO 2 content in the atmosphere in 2019 was much beyond preindustrial levels, which has intensified global warming and caused anomalous climate change. Meanwhile, a vast number of environmentally harmful pollutants and toxins (NO x , SO x , organic pollutants) arising from fossil fuel combustion are discharged into the air and water bodies, posing a danger to the ecosystem and contributing to pollution-related diseases. − To ensure global sustainability, developing environmentally benign and energy-efficient technologies to decrease the CO 2 concentration and eliminate environmental pollutants should therefore be our goal.…”