Work

The effect of heat-treatment on Ag nanocube surface structures and low-temperature isopropanol dehydrogenations

Year: 2025

Type: article

Abstract: Ag nanocubes have drawn much attention in catalytic field recently. As poly-vinylpyrrolidone (PVP) molecules were used as capping ligands, the catalytic activities of the as-synthesized Ag nanocubes are low as PVP molecules block contacts of reactants with metallic Ag surfaces. The current work carefully studied the thermal degradation of PVP under different heat-treatment conditions and the effect on the surface structures of Ag nanocubes with UV–vis spectroscopy, X-ray photoelectron spectroscopy, Raman scattering, Fourier transformed infrared spectrometer, and transmission electron microscopy. The result showed that all the atmosphere, time, and temperatures of heat-treatments affected the PVP thermal degradation and Ag nanocube surface structures. The PVP thermal degradation around 200 °C did not generate amorphous graphite carbon, but should form the “ polyuamide-polyene ”- like structures over Ag nanocube surfaces. The heat-treatment in air degraded more PVP and led to exposures of more metallic Ag surfaces. It was seen that the “C-F” XPS signals appeared after heat-treatment in air, which arose from CF 3 COO- groups and their degradation products over metallic Ag nanocube surfaces. Isopropanol dehydrogenations were conducted at near-room temperatures, and it is seen that the activities showed a sharp increase with different heat-treatment conditions; this was closely related with the appearance of “C-F” XPS signals. Therefore, the result also supported that the “C-F” species over the metallic Ag surfaces might be important for isopropanol dehydrogenations, in additional to the exposed metallic surfaces.

Source: Journal of Alloys and Compounds

DOI: 10.1016/j.jallcom.2025.183095

Authors: Liping Wen, Yao Liu, Man Li, Yanan Chen, Baoshun Liu

Institutions: Wuhan Technology and Business University, Wuhan University of Technology, State Key Laboratory of Silicate Materials for Architecture

Language: English

Topic: Catalytic Processes in Materials Science

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $3,660

Funders: Hubei Provincial Department of Education, National Natural Science Foundation of China, Natural Science Foundation of Hubei Province, National Key Research and Development Program of China