Surface Defect Engineering of CsPbBr₃ Nanocrystals for High Efficient Photocatalytic CO₂ Reduction

Abstract

Converting CO2 into chemical fuels with sunlight is a very attractive approach to solve the greenhouse effect and fossil fuel crisis. Metal halide perovskite nanocrystals (NCs) have been identified as ideal semiconductor photocatalysts for photocatalytic CO2 reduction due to their unique properties, such as strong light absorption, low exciton binding energy, tunable bandgaps, and low cost. However, the pristine perovskite NCs suffering from inevitable defects, which lower their charge transfer efficiency and are detrimental to photocatalytic performance toward CO2 reduction. Herein, a facile approach to modify the surface defects of CsPbBr3 NC is demonstrated using tetrafluoroborate salts as defects treatment agent and loading Co2+ as a cocatalyst. As a result, the optimized Co2+ on the surface of defect‐free CsPbBr3‐BF4 shows a remarkable photocatalytic CO2 activity of 83.8 μmol g−1 h−1, which indicates that the surface modification can effectively suppress the undesired charge recombination in CsPbBr3 NC and promote its charge separation efficiency. This work provides an effective method to modify the surface defects of the CsPbBr3 NCs for high efficient photocatalytic CO2 reduction and broadens the photocatalytic applications of halide perovskites.

Tailoring Inorganic Halide Perovskite Photocatalysts toward Carbon Dioxide Reduction

“…Stability issues can also be addressed by introducing surface defect (Wang et al), surface ligand density control (Chen et al), and so on. [ 48,67,68 ] 3) To further improve the photocatalytic efficiency, there are several aspects to work on, such as increasing the specific surface area, introducing more active sites for CO 2 adsorption, facilitating the separation of photogenerated electron–hole pairs and suppressing the recombination of charges, improving the light‐harvesting property of the photocatalysts, tailoring the surface property of PVKs, and so on. Strategies like defect engineering or cocatalyst modification could influence the reaction intermediate adsorption of PVK, which is promising to adjust the CO 2 RR selectivity.…”

“…Through two steps of the electrostatic self‐assembly method, Wang et al applied tetrafluoroborate salts (BF 4 ) as CsPbBr 3 defects treatment agent and Co 2+ doping to remove uncoordinated Pb adatoms, suppress charge recombination, enhance reduction activity, and improve the performance of photocatalysts, as shown in Figure 4b. [ 48 ] With the optimum Co‐loading amount of 2.0 μmol, the CsPbBr 3 ‐BF 4 /Co shows the photocatalytic activity of 83.8 μmol g −1 h −1 in EA/isopropyl alcohol (IPA) under 100 mW cm −2 illumination.…”

A Novel Synergetic Effect Between Ru and CeO2 Nanoparticles Leads to Highly Efficient Photothermocatalytic CO2 Reduction by CH4 with Excellent Coking Resistance

“…Photocatalytic CO 2 reduction provides a very promising strategy of converting CO 2 to solar fuels as well as realizing the storage of solar energy, which has aroused extensive interest. [ 1–21 ] For the photocatalytic CO 2 reduction strategy, the key challenges to be tackled are its low fuel production rate ( r fuel ) and light‐to‐fuel efficiency ( η ). Extensive efforts have been devoted to tackling the challenges by designing various efficient photocatalysts which could utilize visible, even infrared, energy in sunlight.…”

“…Extensive efforts have been devoted to tackling the challenges by designing various efficient photocatalysts which could utilize visible, even infrared, energy in sunlight. [ 1–21 ]…”

H2S Involved Photocatalytic System: A Novel Syngas Production Strategy by Boosting the Photoreduction of CO2 While Recovering Hydrogen from the Environmental Toxicant

“…As is known, construction of heterojunction, combined with crystal facet engineering, energy band engineering, and structural optimization, has been generally recognized and applied in recent years. [4,[15][16][17][18][19][20][21][22][23] On this basis, the introduction of sacrificial agents, such as ascorbic acid, [24,25] triethanolamine, [26,27] and isopropanol (IPA), [28,29] etc., to consume h + is also effective to promote the reduction reactions stimulated by photogenerated electrons (e − ). Moreover, the photocorrosion of photocatalysts can also be alleviated at the same time, thus endowing them enhanced stability and prolonged service life.…”