Photoreduction of CO2 into CH4 using Bi2S3-TiO2 double-layered dense films

Preparation and Characterization of PEBAX-5513/AgBF4/BMIMBF4 Membranes for Olefin/Paraffin Separation

In this study, we investigated a poly(ether-block-amide)-5513 (PEBAX-5513)/AgBF4/1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) composite membrane, which is expected to have a high stabilizing effect on the Ag+ ions functioning as olefin carriers in the amide group. Poly(ethylene oxide) (PEO) only consists of ether regions, whereas the PEBAX-5513 copolymer contains both ether and amide regions. However, given the brittle nature of the amide, the penetration of BMIMBF4 remains challenging. The nanoparticles did not stabilize after their formation in the long-term test, thereby resulting in a poor performance compared to previous experiments using PEO as the polymer (selectivity 3; permeance 12.3 GPU). The properties of the functional groups in the polymers were assessed using Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis, which confirmed that the properties endowed during the production of the film using the ionic liquid can impact the performance.

Carbon Dioxide Photoreduction on the Bi2S3/MoS2 Catalyst

The photocatalytic activity of a material is contingent on efficient light absorption, fast electron excitation, and control of the recombination rate by effective charge separation. Inorganic materials manufactured in unique shapes via controlled synthesis can exhibit significantly improved properties. Here, n-type Bi2S3 nanorods (with good optical activity) were wrapped with two-dimensional (2D) p-type MoS2 sheets, which have good light absorption properties. The designed p-n junction Bi2S3/MoS2 composite exhibited enhanced light absorption over the entire wavelength range, and higher carbon dioxide adsorption capacity and photocurrent density compared to the single catalysts. Consequently, the activity of the 1Bi2S3/1MoS2 composite catalyst for the photocatalytic reduction of carbon dioxide was more than 20 times higher than that of the single catalysts under visible-light irradiation at ≤400 nm, with partial selectivity for CO conversion. This is attributed to the p-n heterojunction Bi2S3/MoS2 composite designed in this study, the high light absorption of n-Bi2S3, accelerated electron excitation, and the electron affinity of the 2D sheet-p-MoS2, which quickly absorbed excited electrons, resulting in effective charge separation. This ultimately improved the catalytic performance by continuously supplying catalytically active sites to the heterojunction interfaces.

Bismuth-Based Photocatalysts for Solar Photocatalytic Carbon Dioxide Conversion

Photocatalytic CO₂ conversion into solar fuels is an effective means for simultaneously solving both the greenhouse effect and energy crisis. In the past ten years, bismuth-based photocatalysts for environmental remediation have experienced a golden period of development. However, solar photocatalytic CO₂ conversion has only been developed over the past five years and, until now, no reviews have been published on bismuth-based photocatalysts for the photocatalytic conversion of CO₂ . For the first time, solar photocatalytic CO₂ conversion systems are reviewed herein. Synthetic methods and photocatalytic CO₂ performances of bismuth-based photocatalysts, including Sillén-structured BiOX (X=Cl, Br, I); Aurivillius-structured Bi₂ MO₆ (M=Mo, W); and Scheelite-structured BiVO₄ , Bi₂ S₃ , BiYO₃ , and BiOIO₃ , are summarized. In addition, activity-enhancing strategies for this photocatalyst family, including oxygen vacancies, bismuth-rich strategy, facet control, conventional type II heterojunction, Z-scheme heterojunction, and cocatalyst deposition, are reviewed. Finally, the main mechanistic research methods, such as in situ FTIR spectroscopy and theoretical calculations, are presented. Challenges and research trends reported in studies of bismuth-based photocatalysts for photocatalytic CO₂ conversion are discussed and summarized.

Developmental trends in CO2 methanation using various catalysts

Co₂ methanation-two edged sword to counter global warming and energy crisis.