Single‐atom catalysts (SACs), as homogeneous catalysts, have been widely explored for chemical catalysis. However, few studies focus on the applications of SACs in enzymatic catalysis. Herein, we ...report that a zinc‐based zeolitic‐imidazolate‐framework (ZIF‐8)‐derived carbon nanomaterial containing atomically dispersed zinc atoms can serve as a highly efficient single‐atom peroxidase mimic. To reveal its structure–activity relationship, the structural evolution of the single‐atom nanozyme (SAzyme) was systematically investigated. Furthermore, the coordinatively unsaturated active zinc sites and catalytic mechanism of the SAzyme are disclosed using density functional theory (DFT) calculations. The SAzyme, with high therapeutic effect and biosafety, shows great promises for wound antibacterial applications.
Single‐atom nanozyme: A ZIF‐8‐derived Zn–N–C single‐atom catalyst is an efficient single‐atom nanozyme (SAzyme). The SAzyme, which contains unsaturated Zn–N4 sites, shows excellent peroxidase‐like activity and high antibacterial activity against P. aeruginosa, and it is an effective antibacterial agent for wound treatment.
CdS with different morphologies were prepared by simple methods (mainly by water bath) with different solvents, including CdS nanoparticles (CdS-0), CdS nanorods (CdS-1), CdS nanosheets (CdS-2), and ...CdS nanospheres (CdS-3). The structures and morphologies of as-prepared samples were characterized by XRD, XPS, UV–vis DRS, TEM, and SEM. All the prepared samples were used for the photoreduction of Cr (VI) to characterize the photocatalytic performance. CdS-1 shows the highest photocatalytic efficiency was prepared by simply stirring using ethylenediamine as solvent and thiourea as the sulfur source; 98.4% of Cr (VI) can be reduced to Cr (III) within 25 min. The increased photocatalytic activity can be attributed to the high crystallinity and purity, fast separate efficiency, and migration efficiency of electrons (e
−
) and holes (h
+
), as well. This work showed that morphologies and crystallinities have significant impact on the Cr (VI) photoreduction efficiency and introduced a simple method for fabricating samples with different morphologies, which add the knowledge for Cr (VI) reduction. Hoping our work can provide a tendency to fabricate efficient photocatalysis via a simple method.
Mixed metal or transition metal oxides hold an unveiled potential as one of the most promising energy storage material because of their excellent stability, reliable conductivity, and convenient use. ...In this work, CuMnO2 nanoparticles are successfully prepared by a facile hydrothermal process with the help of dispersing agent cetyltrimethylammonium bromide (CTAB). CuMnO2 nanoparticles possess a uniform quadrilateral shape, small size (approximately 25 × 25 nm–35 × 35 nm), excellent dispersity, and large specific surface specific (56.9 m2 g−1) with an interparticle mesoporous structure. All these characteristics can bring benefit for their application in supercapacitor. A quasi-solid-state symmetric supercapacitor device is assembled by using CuMnO2 nanoparticles as both positive electrode and negative electrode. The device exhibits good supercapacitive performance with a high specific capacitance (272 F g−1), a maximum power density of 7.56 kW kg−1 and a superior cycling stability of 18,000 continuous cycles, indicating an excellent potential to be used in energy storage device.
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•CuMnO2 nanoparticles are prepared by a simple hydrothermal method.•CuMnO2 nanoparticles are firstly employed as electrode materials for supercapacitor.•Supercapacitor based on CuMnO2 shows the outstanding electrochemical properties.
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•The hierarchical mesoporous hollow nanocubes were successfully prepared via template etching.•The architecture integrates lager specific surface and mesoporous interconnection.•The ...hybrid supercapacitor exhibited a high energy density and excellent cycling stability.
As one of the major materials of supercapacitor, Transitional Metal phosphides have been extensively studied for superior electrical conductivity, rich valences and high electrochemical activity, and the reasonably designed architecture of bimetals phosphides is considered to be very effective for adequately making full of its material advantages and breaking through its flaws of the low rate capability and bad cycle lifespan in applications. Therefore, bimetals phosphides NiCoP with hollow mesoporous structure is rationally prepared by template etching and phosphorization treatment procedure. This delivered high specific capacity of 658.5 C g−1 at a specific current of 1 A g−1, ultra-high rate capability of 66% achieved even at a high specific current of 30 A g−1 and 80.7% cycling stability after 5000 cycles at 20 A g−1, beneficent from the hierarchical mesoporous hollow structure. Moreover, a hybrid supercapacitor was assembled by NiCoP and activated carbon, which achieves an ultra-high energy density of 41.3 Wh kg−1 at the power density of 373.3 W kg−1, as well as high power density of 7058.3 W kg−1 at an energy density 26.7 Wh kg−1, Remarkably, the hybrid supercapacitor remains exceptional cycling stability of 90.8% at 10 A g−1 after 10,000 cycles. Overall suggest that hierarchical mesoporous NiCoP hollow nanocubes electrode material shows great potential as a novel battery-type electrode for supercapacitor.
Photocatalytic technology is considered to be a promising ways to solve the problems of energy crises and environmental pollution, however, it is a challenge to harvest the full sunlight spectrum in ...a particulate photocatalyst with highly efficiency. Herein, a hollow TiO2@C/CdS tandem heterojunction with broad light absorption was designed and fabricated. The carbon layer with appropriate work function not only plays the role of bridge to connect TiO2 and CdS for the efficient light absorption, but also promotes the formation of Z-scheme heterojunctions. The phase structure, morphology, chemical composition, optical and electrochemical performance, as well as possible photocatalytic mechanism were systematically investigated. The photocatalytic performances of the as-fabricated tandem heterojunctions for tetracycline hydrochloride (TCH) degradation and Cr (VI) reduction are nearly twice as high as hollow TiO2/CdS. Such reasonable tandem heterojunctions may provide a new route to fabricate particulate photocatalyst with highly efficiency.
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•Carbon was used as substitute to construct the tandem Z-scheme heterojunctions.•Carbon bridged tandem Z-scheme heterojunctions were successfully synthesized.•The as-obtained heterojunctions exhibited superior photocatalytic activities.•Carbon layer promoted the transfer and separation of photoinduced charge carriers.
Single‐atom catalysts (SACs), as homogeneous catalysts, have been widely explored for chemical catalysis. However, few studies focus on the applications of SACs in enzymatic catalysis. Herein, we ...report that a zinc‐based zeolitic‐imidazolate‐framework (ZIF‐8)‐derived carbon nanomaterial containing atomically dispersed zinc atoms can serve as a highly efficient single‐atom peroxidase mimic. To reveal its structure–activity relationship, the structural evolution of the single‐atom nanozyme (SAzyme) was systematically investigated. Furthermore, the coordinatively unsaturated active zinc sites and catalytic mechanism of the SAzyme are disclosed using density functional theory (DFT) calculations. The SAzyme, with high therapeutic effect and biosafety, shows great promises for wound antibacterial applications.
Einzelkämpfer: Ein von ZIF‐8 abgeleiteter Zn‐N‐C‐Einzelatomkatalysator wirkt als effizientes Einzelatom‐Nanozym (SAzym). Das SAzym enhält ungesättigte Zn‐N4‐Zentren und zeigt eine hervorragende Peroxidase‐ähnliche Aktivität sowie hohe antibakterielle Aktivität gegen P. aeruginosa. Es ist ein effektives antibakterielles Agens für die Wundbehandlung.
The highly stable photocatalytic semiconductor Zn0.78Cd0.22S and SnS2 were combined to form a novel Z-scheme heterojunction successfully by using a simple and mild hydrothermal method. In this work, ...by combining Zn0.78Cd0.22S with SnS2, the composite Zn0.78Cd0.22S/SnS2 increased the absorption range of visible light relative to the pristine Zn0.78Cd0.22S, thus greatly improving the degradation rate of organic dyes, such as Rhodamine B. Different proportions of SnS2/Zn0.78Cd0.22S were prepared by controlling the weight of SnS2. Through transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM), it can be observed that Zn0.78Cd0.22S took hexagonal SnS2 as the carrier and gathered on SnS2. Moreover, it can be seen from the XPS, after Zn0.78Cd0.22S was combined with SnS2 to form heterojunction, the peaks of some elements were shifted, which indicated that there was some electron movement between the interface of Zn0.78Cd0.22S and SnS2. This phenomenon confirming the success of heterogeneous structure construction. It can also be observed directly from the UV–visible diffuse reflection spectrum (DRS), the SnS2/Zn0.78Cd0.22S increased its response range to visible light. Through ESR data analysis, the Z-scheme SnS2/Zn0.78Cd0.22S increased the generation rate of hydroxyl radical and superoxide radicals of this photocatalytic material, thus improving the photocatalytic performance. The photocatalytic activity of SnS2/Zn0.78Cd0.22S of different proportions was detected by the degradation degree of Rhodamine B and the photoreduction of Cr (Ⅵ). When the composite ratio was 10%, the photocatalytic performance of the material was the most outstanding.
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•A novel composite photocatalyst of SnS2/Zn0.78Cd0.22S was synthesized.•The synthesis method was simple and mild.•SnS2/Zn0.78Cd0.22S Z-scheme heterojunction can reduce the recombination of electron-hole.•Photocatalytic mechanism of SnS2/Zn0.78Cd0.22S was proposed.
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•A novel composite photocatalyst of Ni(OH)2/Bi2MoO6 was synthesized.•Ni(OH)2/Bi2MoO6 heterojunction can reduce the recombination of electron-hole.•Photocatalytic mechanism of ...Ni(OH)2/Bi2MoO6 was proposed.
The stable Ni(OH)2 ultrafine nanosheet combined with Bi2MoO6 to form heterojunction have been fabricated successfully by a simple and mild one-step solvent-thermal method. In this work, the Ni(OH)2/Bi2MoO6heterojunction increased the absorption range of visible light compared to the pure Bi2MoO6, from the UV–visible diffuse reflectance spectrum (DRS), thus greatly improving the degradation rate of organic dyes. The Ni(OH)2/Bi2MoO6heterojunctionwith different proportions was prepared by a mild one-step solvothermal method by controlling the mass fraction ratio between the nickel source and the bismuth source. The morphology and structure of the heterojunction materials were characterized by afield emission scanning electron microscopy (SEM) and a field-emission high-resolution transmission electron microscope (TEM). In this experiment, the photocatalytic properties were demonstrated by the degradation of organic dye Rhodamine B by the prepared samples. The results showed that 2%Ni(OH)2/Bi2MoO6 composite had the strongest photocatalytic performance and the maximum degradation rate was about 98% (135 min) when the Rhodamine B was degraded by visible light irradiation. It also can be found that Bi2MoO6composited by Ni(OH)2ultrafine nanosheet, compared with pure Bi2MoO6, the photocatalytic performance is improved by decreasing the recombination rate of photogenic carriers.
