Vai trò của GO trong tăng cường hoạt tính xúc tác của vật liệu nano tổ hợp MnO2-GO cho cảm biến đo màu

Abstract

Graphene oxide (GO) has been regarded as an important component in functional materials, particularly for developing a variety of catalysts due to its large specific surface area and high charge mobility. In this article, MnO 2-GO nanomaterial was successfully synthesised using a chemical method to investigate the impact of GO on its catalytic activity. The results demonstrated that the presence of GO not only facilitated the uniform dispersion of MnO 2 nanoparticles on its surface but also significantly increased the electrochemically active surface area (by 1.162-fold) and the charge transfer rate (by 2.5-fold) compared to pure MnO₂. The results of catalytic activity evaluation, assessed through the oxidation of 3,3,5,5-tetramethylbenzidine (TMB), revealed that the MnO₂-GO nanomaterial exhibited much higher catalytic efficiency. Specifically, the absorbance peak at 450 nm for the MnO₂-GO-TMB system was 5.82 times higher than that of MnO₂-TMB system, accompanied by a distinct color change from blue to yellow, which was easily observable by the naked eye. The obtained results suggest that the MnO₂-GO nanomaterial is a promising candidate for colorimetric sensor applications.