Search

Atopic dermatitis (AD) is one of the most common allergic skin disorders affecting over 230 million people worldwide, while safe and efficient therapeutic options for AD are currently rarely available. Reactive oxygen species (ROS) accumulation plays a key role in AD's disease progression. Therefore, a novel single-atom catalyst is designed with isolated Cu 1 -N 4 sites anchored on carbon support (Cu 1 -N 4 ISAC), featuring triple antioxidant enzyme-mimicking activities, for efficient AD cascade catalytic therapy (CCT). The excellent superoxide dismutase (SOD)-, glutathione peroxidase (GPx)-, and ascorbate peroxidase (APx)-like activities of Cu 1 -N 4 ISACs enable the sequential conversion of O 2 • - to H 2 O 2 and then to harmless H 2 O, thereby protecting keratinocytes from oxidative stress damage. Notably, two novel experimental methods are developed to directly prove the SOD-GPx and SOD-APx cascade catalytic activities for the first time. In vivo experiments show that Cu 1 -N 4 ISACs are more potent than a recommended typical medicine (halcinonide solution). Additionally, RNA sequencing and bioinformatic analysis reveal that Cu 1 -N 4 ISACs reduce inflammation and inhibit ROS production by activating PPAR signaling, which is aberrantly reduced in AD. Therefore, the synthesized catalytic medicine offers an alternative to alleviate AD and has the potential to serve as PPAR agonists for treating similar diseases., (© 2024 Wiley‐VCH GmbH.)

One-third of the food produced worldwide is wasted annually and never consumed, of which ≈ 40-50% are perishable vegetables and fruits (VFs). Although various methods are proposed to reduce this loss, high manufacturing costs and food safety concerns pose significant challenges for the preservation of VFs. Herein, a respiration-triggered, self-saving strategy for the preservation of perishable products based on a biomolecular Schiff base composite fabricated by imidization of chitosan and cinnamaldehyde (CS-Cin) is reported. Ripening of VFs produces acid moisture and triggers a Schiff base reaction in CS-Cin, permitting the release of volatile Cin into the storage space. This enables versatile preservation by placing CS-Cin on the side without the need to touch the food, like the desiccant packet in a food packaging bag, while the rotting of VFs is retarded in a self-saving manner. As a result, the lifetimes of broccoli and strawberries are extended from 2 to 8 days. Furthermore, CS-Cin with restored preservative properties can be repeatedly recycled from used CS via imidization with Cin. Compared with conventional techniques, the preservatives are easy to use, versatile, and cost-effective, and the respiration-responsive release of Cin empowers a self-saving approach toward the smart preservation of perishable food., (© 2023 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Formic acid is receiving intensive attention as being one of the most progressive chemical fuels for the electrochemical reduction of carbon dioxide. However, the majority of catalysts suffer from low current density and Faraday efficiency. To this end, an efficient catalyst of In/Bi-750 with InO x nanodots load is prepared on a two-dimensional nanoflake Bi 2 O 2 CO 3 substrate, which increases the adsorption of * CO 2 due to the synergistic interaction between the bimetals and the exposure of sufficient active sites. In the H-type electrolytic cell, the formate Faraday efficiency (FE) reaches 97.17% at -1.0 V (vs reversible hydrogen electrode (RHE)) with no significant decay over 48 h. A formate Faraday efficiency of 90.83% is also obtained in the flow cell at a higher current density of 200 mA cm -2 . Both in-situ Fourier transform infrared spectroscopy (FT-IR) and theoretical calculations show that the BiIn bimetallic site can deliver superior binding energy to the * OCHO intermediate, thereby fundamentally accelerating the conversion of CO 2 to HCOOH. Furthermore, assembled Zn-CO 2 cell exhibits a maximum power of 6.97 mW cm -1 and a stability of 60 h., (© 2023 Wiley-VCH GmbH.)

Diabetic foot ulcers (DFU), one of the most serious complications of diabetes, are essentially chronic, nonhealing wounds caused by diabetic neuropathy, vascular disease, and bacterial infection. Given its pathogenesis, the DFU microenvironment is rather complicated and characterized by hyperglycemia, ischemia, hypoxia, hyperinflammation, and persistent infection. However, the current clinical therapies for DFU are dissatisfactory, which drives researchers to turn attention to advanced nanotechnology to address DFU therapeutic bottlenecks. In the last decade, a large number of multifunctional nanosystems based on the microenvironment of DFU have been developed with positive effects in DFU therapy, forming a novel concept of "DFU nanomedicine". However, a systematic overview of DFU nanomedicine is still unavailable in the literature. This review summarizes the microenvironmental characteristics of DFU, presents the main progress of wound healing, and summaries the state-of-the-art therapeutic strategies for DFU. Furthermore, the main challenges and future perspectives in this field are discussed and prospected, aiming to fuel and foster the development of DFU nanomedicines successfully., (© 2022 The Authors. Advanced Science published by Wiley-VCH GmbH.)

The two-dimensional nanosheets are conducive to not only endow opened surfaces for loading active metal atoms but also boost the mass transfer for the heterogeneous reactions. The challenge is how to load and stabilize single-atoms on nanosheets in high-areal densities. This work reports an efficient micro-gas blasting (MGB) strategy to access versatile noble metal single-atoms/metal oxide nanosheets, including Ir 1 /CoO x , Pd 1 /CeO 2 , etc. Especially for Pt/CeO 2 nanosheets (Pt 1 /CeO 2 -S), the Pt loading is increased to 15 at%. The Pt 1 /CeO 2 -S catalysts from MGB are revealed to possess superior reactivity and tolerance in the model reaction of water-gas shift (WGS). The Pt 1 /CeO 2 -S catalyst exhibit 2-3 times reactivity that of their thicker counterpart, single-atom Pt 1 /CeO 2 microspheric catalyst. Moreover, the single-atom sites in Pt 1 /CeO 2 -S (1-10 %) catalysts are stable in a harsh WGS reaction condition of 10 % CO. This work thus paves a way to access the practical single-atom catalysts., (© 2022 Wiley-VCH GmbH.)

Development of Pt group metal-free catalysts for low-temperature CO oxidation remains critical. In this work, active and stable mesoporous Cu-Ce-O x solid solutions are prepared by using spray pyrolysis. The specific surface areas and pore volumes reach as high as 170 m 2  g -1 and 0.24 cm 3  g -1 , respectively. The results of CO oxidation study suggest that (1) the catalyst obtained by spray pyrolysis possesses much higher activity than those made by co-precipitation, sol-gel, and hydrothermal methods; (2) the optimal Cu 0.2 -Ce 0.8 -O x solid solution presents a reactivity over 28 times that of both single-component CuO and CeO 2 at 70 °C. Based on the study of pure-phase Cu-Ce-O x solid solutions by selective leaching of segregated CuO x species, the active center for CO oxidation is confirmed as the bimetallic Cu-Ce-O site, whereas the individual CuO x particles not only act as spectators but also block the active Cu-Ce-O sites. A low apparent activation energy of approximately 48 kJ mol -1 is detected for CO oxidation at the Cu-Ce-O site, making Cu-Ce-O x solid solutions able to present high activity at low temperature. Furthermore, the Cu-Ce-O x catalysts exhibit excellent stability and thermal tolerance toward CO oxidation., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Efficient, abundant and low-cost catalysts for the oxygen evolution reaction (OER) are required for energy conversion and storage. In this study, a doping-etching route has been developed to access defect rich Fe-Co-Al (Fe-Co-Al-AE) ternary hydroxide nanosheets for superior electrochemical oxygen evolution. After partial etching of Al, ultrathin Fe 3 Co 2 Al 2 -AE electrocatalysts with a rich pore structure are obtained with a shift of the cobalt valence state towards higher valence (Co 2+ →Co 3+ ), along with a substantial improvement in the catalytic performance. Fe 3 Co 2 Al 2 -AE shows a notably lower overpotential of only 284 mV at a current density of 10 mA cm -2 and double the OER mass activity of the etching-free Fe 3 Co 2 Al 2 with an overpotential of 350 mV. Density functional theory shows the leaching of Al changes the rate-determining step of the OER from conversion of *OOH into O 2 on Fe 3 Co 2 Al 2 to formation of OOH from *O on the Al-defective catalysts. This work demonstrates an effective route to design and synthesize transition metal electrocatalysts and provides a promising alternative for the further development of oxygen evolution catalysts., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A mesoporous MnCo 2 O 4 electrode material is made for bifunctional oxygen electrocatalysis. The MnCo 2 O 4 exhibits both Co 3 O 4 -like activity for oxygen evolution reaction (OER) and Mn 2 O 3 -like performance for oxygen reduction reaction (ORR). The potential difference between the ORR and OER of MnCo 2 O 4 is as low as 0.83 V. By XANES and XPS investigation, the notable activity results from the preferred Mn IV - and Co II -rich surface. The electrode material can be obtained on large-scale with the precise chemical control of the components at relatively low temperature. The surface state engineering may open a new avenue to optimize the electrocatalysis performance of electrode materials. The prominent bifunctional activity shows that MnCo 2 O 4 could be used in metal-air batteries and/or other energy devices., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Carbon-based transition-metal oxides are considered as an appropriate anode material candidate for lithium-ion batteries. Herein, a simple and scalable dry production process is developed to produce carbon-encapsulated 3D net-like FeO x /C materials. The process is simply associated with the pyrolysis of a solid carbon source, such as filter paper, adsorbed with ferrite nitrate. The carbon derived from filter paper induces a carbothermal reduction to form metallic Fe, the addition of carbon and iron increase the conductivity of this material. As expected, this 3D net-like FeO x /C composite delivers an excellent charge capacity of 851.3 mAh g -1 after 50 cycles at 0.2 A g -1 as well as high stability and rate performance of 714.7 mAh g -1 after 300 cycles at 1 A g -1 . Superior performance, harmlessness, low costs, and high yield may greatly stimulate the practical application of the products as anode materials in lithium-ion batteries., (© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Graphene-based hybrid nanostructures possess many advantages in the field of electrochemical energy applications. In this work, a facile and efficient hydrothermal approach has been developed for the preparation of NiFe alloy nanoparticles/rGO hybrid nanostructures, in which the nanoparticles are well combined with rGO nanosheets and the size of the nanoparticles is about 100 nm. Moreover, the electrochemical oxygen evolution reaction (OER) tests confirmed that the obtained NiFe/rGO hybrid nanostructures possess notably higher activity than both the rGO-free NiFe nanoparticles and pure Ni/rGO hybrids, and the optimal NiFe ratio is 2:1. The OER overpotential at 20 mA cm(-1-2) with Ni2 Fe/rGO is as low as 0.285 V, which is 96 mV lower than that of pure Ni/rGO hybrids. Meanwhile, the Ni2 Fe/rGO catalyst has excellent stability. Therefore, this work contributes a facile and efficient method to prepare a NiFe alloy nanoparticles/rGO hybrid structure for potential applications in the field of electrochemical energy devices, such as electrochemical water splitting cells, rechargeable metal/air batteries, etc., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Preparing nonprecious metal catalysts with high activity in the oxygen reduction reaction (ORR) can promote the development of energy conversion devices. Support-free porous Mn2 O3 was synthesized by a facile aerosol-spray-assisted approach (ASAA) and subsequent thermal treatment, and exhibited ORR activity that is comparable to commercial Pt/C The catalyst also exhibits notably higher activity than other Mn-based oxides, such as Mn3 O4 and MnO2 . The rotating ring disk electrode (RRDE) study indicates a typical 4-electron ORR pathway on Mn2 O3 . Furthermore, the porous Mn2 O3 demonstrates considerable stability and a good methanol tolerance in alkaline media. In light of the low cost and high earth abundance of Mn, the highly active Mn2 O3 is a promising candidate to be used as a cathode material in metal-air batteries and alkaline fuel cells., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Noble metal nanoparticles (NPs) with 1-5 nm diameter obtained from NaHB4 reduction possess high catalytic activity. However, they are rarely used directly. This work presents a facile, versatile, and efficient aerosol-spray approach to deliver noble-metal NPs into metal oxide supports, while maintaining the size of the NPs and the ability to easily adjust the loading amount. In comparison with the conventional spray approach, the size of the loaded noble-metal nanoparticles can be significantly decreased. An investigation of the 4-nitrophenol hydrogenation reaction catalyzed by these materials suggests that the NPs/oxides catalysts have high activity and good endurance. For 1 % Au/CeO2 and Pd/Al2 O3 catalysts, the rate constants reach 2.03 and 1.46 min(-1) , which is much higher than many other reports with the same noble-metal loading scale. Besides, the thermal stability of catalysts can be significantly enhanced by modifying the supports. Therefore, this work contributes an efficient method as well as some guidance on how to produce highly active and stable supported noble-metal catalysts., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Abundant iron group metal oxides and their composites possess great potential in the application of electrochemical energy storage and conversion. In this work, we obtained Co-Fe-O composites/reduced graphene oxides (CFO/rGO) hybrid structures, engineered their compositions, phase, and structures by a facile hydrothermal route, and studied their composition-dependent activity for electrochemical oxygen evolution reaction (OER) in alkaline media. It is found that synergetic effects bring a clear decrease in overpotential and Tafel slope for CFO/rGO catalysts in comparison with monometallic composition/rGO catalysts. OER charge-transfer resistance is significantly reduced after Fe addition, indicating that the reaction barriers of CFO/rGO are reduced. The optimal CFO/rGO with Co-Fe ratio of 2:1 was identified. Our results on the synergetic effects of CFO/rGO enrich the understanding of iron-group composites for electrocatalytic applications., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

An aerosol-spray-assisted approach (ASAA) is proposed and confirmed as a precisely controllable and continuous method to fabricate amorphous mixed metal oxides for electrochemical water splitting. The proportion of metal elements can be accurately controlled to within (5±5) %. The products can be sustainably obtained, which is highly suitable for industrial applications. ASAA was used to show that Fe6Ni10O(x) is the best catalyst among the investigated Fe-Ni-O(x) series with an overpotential of as low as 0.286 V (10 mA cm(-2)) and a Tafel slope of 48 mV/decade for the electrochemical oxygen evolution reaction. Therefore, this work contributes a versatile, continuous, and reliable way to produce and optimize amorphous metal oxide catalysts., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Bimetallic tubular nanostructures have been the focus of intensive research as they have very interesting potential applications in various fields including catalysis and electronics. In this paper, we demonstrate a facile method for the fabrication of Au-Pt double-walled nanotubes (Au-Pt DWNTs). The DWNTs are fabricated through the galvanic displacement reaction between Ag nanowires and various metal ions, and the Au-Pt DWNT catalysts exhibit high active catalytic performances toward both methanol electro-oxidation and 4-nitrophenol (4-NP) reduction. First, they have a high electrochemically active surface area of 61.66 m(2)  g(-1), which is close to the value of commercial Pt/C catalysts (64.76 m(2) g(-1)), and the peak current density of Au-Pt DWNTs in methanol oxidation is recorded as 138.25 mA mg(-1), whereas those of Pt nanotubes, Au/Pt nanotubes (simple mixture), and commercial Pt/C are 24.12, 40.95, and 120.65 mA mg(-1), respectively. The Au-Pt DWNTs show a markedly enhanced electrocatalytic activity for methanol oxidation compared with the other three catalysts. They also show an excellent catalytic performance in comparison with common Au nanotubes for 4-nitrophenol (4-NP) reduction. The attractive performance exhibited by these prepared Au-Pt DWNTs can be attributed to their unique structures, which make them promising candidates as high-performance catalysts., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Herein we report a gentle seedless and surfactant-free method for the preparation of clean-surface porous platinum nanoparticles. In terms of electrocatalytic CH(3)OH oxidation, the clean-surface porous platinum exhibited better performance than platinum nanoparticles and a commercial Pt/C catalyst. The porous nanostructures exhibited 2.26-fold higher mass activity and 2.8-fold greater specific activity than the Pt/C catalyst. More importantly, three typical surfactants, cetyltrimethylammonium bromide/chloride (CTAB/C), poly(vinylpyrrolidone), and sodium dodecyl sulfate, were chosen to study the inhibition effect of surfactants on electrocatalytic performance. It was observed that the surfactants led to a clear selective decrease in electrocatalytic performance. CTAB/C inhibited the catalytic activity the most due to the stronger interaction between the OH-enriched platinum surface and the positively charged molecules. Thus, this work indicates that these clean-surface porous platinum nanoparticles may be used as efficient catalysts for direct methanol fuel cells and provides a greater understanding of the inhibition effects of surfactants on catalytic activity., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

In this work, we utilize the galvanic displacement synthesis and make it a general and efficient method for the preparation of Au-M (M = Au, Pd, and Pt) core-shell nanostructures with porous shells, which consist of multilayer nanoparticles. The method is generally applicable to the preparation of Au-Au, Au-Pd, and Au-Pt core-shell nanostructures with typical porous shells. Moreover, the Au-Au isomeric core-shell nanostructure is reported for the first time. The lower oxidation states of Au(I), Pd(II), and Pt(II) are supposed to contribute to the formation of porous core-shell nanostructures instead of yolk-shell nanostructures. The electrocatalytic ethanol oxidation and oxygen reduction reaction (ORR) performance of porous Au-Pd core-shell nanostructures are assessed as a typical example for the investigation of the advantages of the obtained core-shell nanostructures. As expected, the Au-Pd core-shell nanostructure indeed exhibits a significantly reduced overpotential (the peak potential is shifted in the positive direction by 44 mV and 32 mV), a much improved CO tolerance (I(f)/I(b) is 3.6 and 1.63 times higher), and an enhanced catalytic stability in comparison with Pd nanoparticles and Pt/C catalysts. Thus, porous Au-M (M = Au, Pd, and Pt) core-shell nanostructures may provide many opportunities in the fields of organic catalysis, direct alcohol fuel cells, surface-enhanced Raman scattering, and so forth., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Much effort has gone into generating polyhedral noble metal nanostructures because of their superior electrocatalytic activities for fuel cells. Herein, we report uniform, high-yield icosahedral silver and gold nanoparticles by using a facile one-pot, seedless, water-based approach that incorporates polyvinyl pyrrolidone and ammonia. Electrocatalysis of the oxygen-reduction reaction was carried out in alkaline media to evaluate the performance of the icosahedral nanoparticles. They showed excellent stability and much higher electrocatalytic activity than the spherelike nanoparticles; they display a positive shift in reduction peak potential for O(2) of 0.14 and 0.05 V, while the reduction peak currents of the silver and gold icosahedra are 1.5- and 1.6-fold, respectively, better than the spherelike nanoparticles. More importantly, the icosahedral nanoparticles display electrocatalytic activities comparable with commercial Pt/C electrocatalysts. The facile preparation of icosahedral silver and gold nanoparticles and their superior performance in the oxygen reduction reaction render them attractive replacements for Pt as cathode electrocatalysts in alkaline fuel cells., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)