Highly Dispersed Pt Nanoparticle-Doped Mesoporous ZnO Photocatalysts for Promoting Photoconversion of CO2 to Methanol

Soha M Albukhari; Adel A Ismail

doi:10.1021/acsomega.1c03259

Highly Dispersed Pt Nanoparticle-Doped Mesoporous ZnO Photocatalysts for Promoting Photoconversion of CO₂ to Methanol

ACS Omega. 2021 Sep 3;6(36):23378-23388. doi: 10.1021/acsomega.1c03259. eCollection 2021 Sep 14.

Authors

Soha M Albukhari¹, Adel A Ismail^{2

3}

Affiliations

¹ Chemistry Department, Faculty of Science, King Abdulaziz University, P.O. Box 80200, Jeddah 21589, Saudi Arabia.
² Central Metallurgical R&D Institute, CMRDI, P.O. Box 87, Helwan, Cairo 11421, Egypt.
³ Nanotechnology and Advanced Materials Program, Energy & Building Research Center, Kuwait Institute for Scientific Research (KISR), P.O. Box 24885, Safat 13109, Kuwait.

Abstract

Photoreduction of CO₂ is considered a challenge due to the lack of effective photocatalysts with wide-spectrum absorption, active charge separation dynamically, and CO₂ adsorption. Herein, mesoporous Pt/ZnO nanocomposites with different Pt percentages (0.5-2%) have been fabricated using the sol-gel process in the presence of a template for CO₂ photoreduction during visible-light exposure. Pt nanoparticles (NPs) deposited onto mesoporous ZnO with a considerable surface area can effectively promote charge mobility. The mesoporous 1.5% Pt/ZnO nanocomposite exhibits an optimal CH₃OH yield (668 μmol g^-1), which is 18.5-fold larger than that of mesoporous ZnO (36 μmol g^-1). The most photoactive material was the 1.5% Pt/ZnO nanocomposite, producing CH₃OH of 668 μmol g^-1, and the production rate of CH₃OH over the 1.5% Pt/ZnO nanocomposite (74.11 μmol g^-1 h^-1) was increased 20 times in comparison with ZnO NPs (3.72 μmol g^-1 h^-1). The enhancement of CO₂ photoreduction efficiency over Pt/ZnO nanocomposites was attributed to the formation of the heterojunction at the Pt/ZnO interface, promoting a lower resistance to charge transfer and a larger electron transfer to the conduction band. Mesoporous Pt/ZnO nanocomposites offer enhanced accessibility and a larger surface area. Such an unparalleled mesostructure provides a new framework for the construction and design of photoactive materials with high-efficiency photocatalysts.