Photodeposited TiO 2 /Ag nanocomposites were generally used to be a friendly catalyst for degrading organic contaminant in environmental field. However, electrochemiluminescence (ECL) sensing analysis based on photocatalysts remains a significant challenge. Herein, polyvinylimide (PEI)-TiO 2 /Ag nanocomposites (PEI-TiO 2 /AgNCPs) film with reduced graphene oxide(r-GO) was constructed as a sensing interface for copper(II) ECL detection. TiO 2 /Ag nanocomposites was prepared by reversed phase microemulsion method and photodeposition technique. Moreover, it was discovered that a small amount of Cu 2+ could obviously boost the ECL signal of ninhydrin-hydrogen peroxide system. Signal amplification was achieved by using the synergistic effect between r-GO and TiO 2 /Ag nanocomposites, and the efficiently concentrated effect of PEI to Cu 2+ . Furthermore, the investigation showed that ECL mechanism of ninhydrin-hydrogen peroxide system was attributed to the generated hydroxyl radical and superoxide anion during the several type of reactions. Thus for the first time, an ultrasensitive ECL approach for detecting Cu 2+ could be performed using ninhydrin as an ECL signal probe and hydrogen peroxide as a co-reaction reagent. Under the suitable circumstances, the proposed method showed an excellent linear relationship in the concentration range of Cu 2+ from 1.0 fM to 5.0 nM. Detection limit was estimated to be as low as 0.26 fM. The sensing interface expanded the application of photodeposited TiO 2 /Ag nanocomposites in ultrasensitive ECL detection. It has potential applications in other components and biological analysis.
Microplastics (MPs) pose significant environmental and health risks, and conventional disposal methods often suffer from inefficiency and potential ecological harm. Photocatalytic degradation has emerged as a promising solution. However, traditional TiO 2 -based photocatalysts are limited by high electron–hole recombination rates, narrow visible light absorption, and poor reusability. In this study, we develop and optimize a Fe 3 O 4 @TiO 2 /Ag nanocomposite for the efficient degradation of polyethylene (PE) MPs with facile recovery. The synergistic integration of Fe 3 O 4 and Ag with TiO 2 enhances visible light absorption and mitigates charge carrier recombination. Notably, the Fe 3 O 4 @TiO 2 /Ag nanocomposite exhibits a degradation efficiency of 15.54%, outperforming Fe 3 O 4 @TiO 2 (12.63%) and pristine TiO 2 (1.15%). Moreover, the composite maintains its performance over five consecutive cycles, underscoring its durability. The degradation efficiency of Fe 3 O 4 @TiO 2 /Ag was further optimized using response surface methodology. Overall, the developed Fe 3 O 4 @TiO 2 /Ag nanocomposite exhibits excellent photocatalytic efficiency, magnetic recoverability, and long-term stability, highlighting its potential for practical applications in mitigating microplastic pollution.
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