Visible-Light-Driven CO2 Reduction into Methanol Utilizing Sol-Gel-Prepared CeO2-Coupled Bi2O3 Nanocomposite Heterojunctions

Abstract

Carbon dioxide (CO2) photoreduction into renewable fuels over semiconductor photocatalysts has emerged as a green and sustainable alternative for energy production. Consequently, tremendous efforts are being performed to develop robust and sustainable photocatalysts. Therefore, visible-light active nanocomposite photocatalysts composed of 5.0–20.0 wt.% bismuth oxide (Bi2O3) and cerium oxide (CeO2) were synthesized by a sol-gel-based process. The prepared nanocomposites were evaluated for the promoted photocatalytic reduction of CO2 into methanol (CH3OH). Various characterizations of the obtained photocatalysts exposed an outstanding development of crystalline structure, morphology, and surface texture due to the presence of Bi2O3. Moreover, the absorbance of light in the visible regime was improved with enhanced charge separation, as revealed by the exploration of optical response, photoluminescence, and photocurrent measurements. The overall bandgap calculations revealed a reduction to 2.75 eV for 15% Bi2O3/CeO2 compared to 2.93 eV for pure CeO2. Moreover, the adjusted 2.8 g L−1 dose of 15% Bi2O3/CeO2 selectively produced 1300 μmol g−1 CH3OH after 9 h of visible light irradiation. This photocatalyst also exhibits bearable reusability five times. The improved progression of 15% Bi2O3/CeO2 is denoted by significant charge separation as well as enhanced mobility. This study suggests the application of metal oxide-based heterojunctions for renewable fuel production under visible light.

Visible Light Active Ce-Doped and Cu–Ce co-doped TiO2 Nanocrystals and Optofluidics for Clean Alcohol Production from CO2

“…Figure compares the optimal production rates for ethanol and methanol obtained in the present work with those reached in different visible-light-driven systems in the last years using aqueous solutions, although different photocatalysts, electrolytes, light intensities, and photoreactor configurations were employed. ,,,,,− The literature reports a maximum production of ethanol of 51.8 μmol·g –1 ·h –1 from direct CO 2 photoconversion using abundant red phosphorus and Bi 2 MoO 6 as a photocatalyst . Nevertheless, this value has been recently improved (218.2 μmol·g –1 ·h –1 ) by developing an innovative photoactive porous titania-based metal–organic aerogel with a meso/macroporous structure that facilitates the diffusion of CO 2 and reduction products in an optofluidic microreactor, resulting in unprecedented methanol production from CO 2 photoreduction (786 μmol·g –1 ·h –1 ).…”

The synergistic chemical coupling of nanostructured MoS2 with nitrogen-deficient 2-D triazine-based polymeric m-C3Nx for efficient and selective CO2 photocatalytic conversion to CO

“…DFT calculations were performed using the plane wave method as implemented in the Quantum ATK package. 44 All calculations were performed using the projector augmented wave (PAW) method and generalized-gradient approximation (GGA) of the Perdew-Burke-Ernzerhof (PBE) correlation functional. 45 The energy cut-off was set to 500 eV for the plane wave basis set.…”

“…[25][26][27][28] Therefore, it has been coupled with reduced graphene oxide, MXene, [29][30][31] g-C 3 N 4 , [31][32][33][34][35] and black phosphorus. 36,37 In these heterostructures, the face-to-face coupling of MoS 2 has been reported, where the stacking in the parallel position between MoS 2 and g-C 3 N 4 provides less cross-sectional area for the interfacial electronic coupling and photogenerated charge carrier transfer. Nonetheless, the 2H basal planes (002), (100), and (110) of MoS 2 , empowered by the hexagonal symmetry of MoS 2 , exhibit high catalytic activity.…”

Construction of a novel S-type γ-Bi2O3/CeO2 heterojunction for highly efficient photocatalytic degradation of antibiotics

“…32 The CeO 2 /b-Bi 2 O 3 could remove the dyes, antibiotics, and NO, while the improvement quantities were lower than 20%. [33][34][35][36][37] In the above studies, the a-Bi 2 O 3 and b-Bi 2 O 3 constituted a II-type and a direct Z-type heterojunction with CeO 2 to enhance the photocatalytic performance. For the II-type heterojunction, the electrons transfer on the conduction band (CB) of the two semiconductors and the holes migrate on their valence band (VB).…”