Magnetically Separable Fe₃O₄@CdS Type‐II Nanohybrids with Excellent Photocatalytic Activity and Antibacterial Properties

Abstract

A magnetically separable Fe3O4@CdS type‐II core–shell nanohybrid (NH) photocatalyst, with excellent antibacterial properties and photocatalytic activity, was synthesized and characterized by means of structural, elemental, and morphological analyses. Steady‐state and time‐resolved emission and absorption spectroscopy were also exploited to realize the location of charge‐carrier wave functions in the NHs. The antibacterial activity of NHs was then evaluated against Escherichia coli (1.4×108 CFU mL−1; CFU=colony forming units) and Staphylococcus saprophyticus (1.2×108 CFU mL−1) as model strains of Gram‐negative and ‐positive microbes. Compared with CdS and Fe3O4, the as‐synthesized Fe3O4@CdS composite exhibited highly improved bactericidal activity and recyclability. Concentration values of 5.0 and 4.0 mg mL−1 were required for Fe3O4@CdS NHs to inhibit the growth of E. coli and S. saprophyticus, respectively. The contribution of OH. radicals to photocatalysis at the Fe3O4@CdS surface was also considered. Moreover, thiobarbituric acid reactive substances and protein carbonyl assay protocols have been exploited to monitor levels of oxidative damage to lipids and proteins in cells. Additionally, the photocatalytic activity of Fe3O4@CdS NHs was monitored for the degradation of xylenol orange dye. Compared with CdS and Fe3O4, as‐synthesized Fe3O4@CdS displayed superior performances in the photodegradation of xylenol orange. Possible mechanisms involved in the degradation of xylenol orange are also discussed.

Hydrangea‐like ZnS/ZnIn 2 S 4 microspheres with outstanding photocatalytic degradation of xylenol orange and thymol blue under vis irradiation

“…Blank test without photocatalyst only exhibits no photodegradation under visible light. ZnS/ZnIn 2 S 4 microspheres exhibit obviously higher photocatalytic degradation than the blank test where 40 min irradiation leads the complete degradation of XO, which is also less than 120 min for ZnS of Ye et al [32] and 180 min for Fe 3 O 4 @CdS of Abdolraouf et al [33]. It demonstrates that the ZnS/ZnIn 2 S 4 microspheres can serve as a kind of photocatalytic material for XO degradation.…”

Visible‐Light‐Mediated Oxidative Amidation of Aldehydes by Using Magnetic CdS Quantum Dots as a Photocatalyst

“…More recently, some magnetic supported CdS photocatalysts have been developed. For example, Samadi‐Maybodi and co‐workers have synthesized Fe 3 O 4 /CdS nanohybrids that displayed superior photocatalytic activity toward the degradation of xylenol orange [66] . The CdS/C@Fe 3 O 4 nanoreactor has been synthesized through the surface‐imprinting technique and applied as a photocatalyst in the photodegradation of ciprofloxacin [67] .…”