Confined Space and Heterojunction Dual Modulation of ZnO/ZnS for Boosting Photocatalytic CO₂ Reduction

Abstract

The reduction of CO2 to chemical fuel driven by solar energy can not only meet the growing demand for renewable energy, but also balance the carbon cycle in nature. However, the current photocatalysts have low CO2 conversion due to their poor light capture ability, narrow light response range, and high recombination probability of photogenerated carriers. Herein, a heterogeneous photocatalyst of hollow structured ZnO/ZnS decorated with Pt nanoparticles is synthesized through the hydrothermal process and photodeposition method, showing excellent photocatalytic activity for CO2 reduction in long‐time stability and ≈100% CO selectivity, which can mainly contribute to natural enhanced light‐capture ability of the hollow confined space due to multiple reflection and scattering of light in the cavity, thus improving separation efficiency of photogenerated charge carriers due to the type II junction constructed between ZnO and ZnS and the additional reaction active sites after decorating Pt nanoparticles in the surface of the hollow structure.

Recent advances in novel materials for photocatalytic carbon dioxide reduction

“…Reproduced with permission: Copyright 2023, John Wiley and Sons. [66] could increase the exposure ratio of the (100) face, thus promoting the C-C coupling of intermediates. GC-MS spectra also confirmed the C-C coupling of C 2 H 5 OH from CO 2 intermediates.…”

“…Furthermore, various other metal oxides have found extensive utility in the realm of PCRR. For instance, Ma et al [ 66 ] constructed a hollow tubular Type‐II ZnO/ZnS heterojunction material, as shown in Figure 4b (i) incident light could undergo multiple scattering or reflection within the cavity, enhancing light capture and utilization. Additionally, the shell facilitated shorter carrier transfer paths, enabling more efficient migration of carriers to the catalyst surface, thereby enhancing their participation in the reaction.…”

Establishing Multiple‐Order Built‐In Electric Fields Within Heterojunctions to Achieve Photocarrier Spatial Separation

“…As depicted in Scheme , Tables S1–S2 and Figures S1–S3 (Supporting Information), the simulation revealed that when semiconductors (0D materials) were exclusively built either on the top or side of the substrates, [ 20 ] the resulting BIEF of the heterojunctions [ 21 ] was only distributed in the vertical or horizontal direction, [ 22 ] signifying a limited range of action. [ 23 ] However, upon simultaneous deposition of ZnS NPs on both the top and side positions, a multiple‐order BIEF with a large range of actions can be realized (Scheme 1c and Figure S4, Supporting Information), guiding the structural design of heterojunctions for CO 2 ‐photoreduction.…”

The Pivotal Roles of Light and Ca‐Doping in Photothermocatalytic CO2 Reduction by Methane on Nanocomposites of Nickel Nanoparticles Loaded on Ca‐Doped Al2O3

“…As a result, the fuel production rate ( r fuel ) and solar‐to‐fuel efficiency ( η ) of photocatalytic reduction of CO 2 are not high enough to meet the requirements of the future practical applications. [ 8–12 ]…”