Latest ArticlesWater electrolysis technology holds the perfect promise of the hydrogen production, yet control of efficiency and rate of water electrolysis greatly relies on the availability of high-performance electrode materials for kinetic-sluggish oxygen evolution reaction (OER). Accordingly, substantial endeavors have been made to explore advanced electrode materials over the past decade. Recently, RuO2 and RuO2-based materials have been demonstrated to be promising for OER due to their remarkable electrocatalytic activity and pH-universal application. Herein, the great achievements and progresses of this flourishing spot are comprehensively reviewed, which are started by a general description of OER to understand the reaction mechanism in detail. Subsequently, the key advantages and issues of RuO2 towards OER are also introduced, followed by proposing many advanced strategies for further promoting the electrocatalytic OER performance of RuO2. Finally, the daunting challenges and future progresses of RuO2 electrocatalysts toward practical water oxidation are highlighted, aiming to provide guidance for the fabrication of desirable RuO2-based electrocatalysts toward OER.
Owing to the special formation of photopolymerized hydrogels, they can effectively control the formation of hydrogels in space and time. Moreover, the photopolymerized hydrogels have mild formation conditions and biocompatibility; therefore, they can be widely used in tissue engineering. With the development and application of manufacturing technology, photopolymerized hydrogels can be widely used in cell encapsulation, scaffold materials, and other tissue engineering fields through more elaborate manufacturing methods. This review covers the types of photoinitiators, manufacturing technologies for photopolymerized hydrogels as well as the materials used, and a summary of the applications of photopolymerized hydrogels in tissue engineering.
Chemodynamic therapy (CDT) is an emerging endogenous stimulation activated tumor treatment approach that exploiting iron-containing nanomedicine as catalyst to convert hydrogen peroxide (H2O2) into toxic hydroxyl radical (·OH) through Fenton reaction. Due to the unique characteristics (weak acidity and the high H2O2 level) of the tumor microenvironment, CDT has advantages of high selectivity and low side effect. However, as an important substrate of Fenton reaction, the endogenous H2O2 in tumor is still insufficient, which may be an important factor limiting the efficacy of CDT. In order to optimize CDT, various H2O2-generating nanomedicines that can promote the production of H2O2 in tumor have been designed and developed for enhanced CDT. In this review, we summarize recently developed nanomedicines based on catalytic enzymes, nanozymes, drugs, metal peroxides and bacteria. Finally, the challenges and possible development directions for further enhancing CDT are prospected.
In this work, the phase-transitioned BSA (PTB) film using the mild and fast fabrication process adhered to the capillary inner wall uniformly, and the fabricated PTB film-coated capillary column was applied to realize open tubular capillary electrochromatography (OT-CEC) enantioseparation. The enantioseparation ability of PTB film-coated capillary was evaluated with eight pairs of chiral analytes including drugs and neurotransmitters, all achieving good resolution and symmetrical peak shape. For three consecutive runs, the relative standard deviations (RSD) of migration time for intra-day, inter-day, and column-to-column repeatability were in the range of 0.3%–3.5%, 0.2%–4.9% and 2.1%–7.7%, respectively. Moreover, the PTB film-coated capillary column ran continuously over 300 times with high separation efficiency. Therefore, the coating method based on BSA self-assembly supramolecular film can be extended to the preparation of other proteinaceous capillary columns.
Being abundant and active, Fe2O3 is suitable for selective oxidation of H2S. However, its practical application is limited due to the poor sulfur selectivity and rapid deactivation. Herein, we report a facile template-free hydrothermal method to fabricate porous α-Fe2O3/SnO2 composites with hierarchical nanoflower that can obviously improve the catalytic performance of Fe2O3. It was disclosed that the synergistic effect between α-Fe2O3 and SnO2 promotes the physico-chemical properties of α-Fe2O3/SnO2 composites. Specifically, the electron transfer between the Fe2+/Fe3+ and Sn2+/Sn4+ redox couples enhances the reducibility of α-Fe2O3/SnO2 composites. The number of oxygen vacancies is improved when the Fe cations incorporate into SnO2 structure, which facilitates the adsorption and activation of oxygen species. Additionally, the porous structure improves the accessibility of H2S to active sites. Among the composites, Fe1Sn1 exhibits complete H2S conversion with 100% sulfur selectivity at 220 ℃, better than those of pure α-Fe2O3 and SnO2. Moreover, Fe1Sn1 catalyst shows high stability and water resistance.
Carbon nanotube film (CNTF) can be used for photocatalysis and water treatment due to its porous structure, good stability and excellent electrical properties. In this work, TiO2/amorphous carbon/carbon nanotube film (TCC) composite with uniform structure was prepared by a simple atomization spraying method. Rhodamine B (RhB) was used to test the photocatalytic activity of TCC. TCC composite exhibits good photocatalytic activity under ultraviolet light. In particular, the degradation efficiency of rhodamine B (RhB) by TCC sprayed with 9 layers of TiO2 (9TCC) increased by 1.45 times than of TiO2 under ultraviolet light. The enhanced photocatalytic activity of TCC is attributed to the CNTF, which can broaden the light response range of TCC and improve the migration efficiency of electrons. The existence of amorphous carbon will promote these advances. Moreover, the better hydrophilic properties would enhance the catalytic performance happened on the solid-liquid interface. Finally, the photocatalytic mechanism and degradation intermediates of the TCC composite were proposed.
A heterojunction of Sm-doped g-C3N4/Ti3C2 MXene (SCN/MX) was constructed via prepolymerization and solid mixture-calcination method. The modified g-C3N4 presented a hollow porous seaweed-like shape which can increase its specific area and active sites. In SCN/MX composite, the optical properties, no matter optical absorption ability or separation performance of photo-induced electrons and holes, were enhanced. Among them, Sm-doping may play an important role on transferring the photogenerated electrons to suppress their recombination, and Ti3C2 MXene would broaden light absorption and further improve the carrier migration efficiency. The SCN/MX presented higher photocatalytic degradation efficiency (> 99%) of ciprofloxacin under visible light irradiation. The quenching experiments and electron spin-resonance spectroscopy confirmed that the dominated active materials were superoxide radical and holes. The degradation mechanisms of ciprofloxacin (CIP) over the SCN/MX were attacking of the active materials on the piperazine ring and quinolone ring, and the final products were CO2, H2O and F−.
Injectable hydrogels have been considered as promising materials for bone regeneration, but their osteoinduction and mechanical performance are yet to be improved. In this study, a novel biocompatible injectable and self-healing nano hybrid hydrogel was on-demand prepared via a fast (within 30 s) and easy gelation approach by reversible Schiff base formed between −CH=O of oxidized sodium alginate (OSA) and −NH2 of glycol chitosan (GCS) mixed with calcium phosphate nanoparticles (CaP NPs). Its raw materials can be ready in large quantities by a simple synthesis process. The mechanical strength, degradation and swelling behavior of the hydrogel can be readily controlled by simply controlling the molar ratio of −CH=O and −NH2. This hydrogel exhibits pH responsiveness, good degradability and biocompatibility. The hydrogel used as the matrix for mesenchymal stem cells can significantly induce the proliferation, differentiation and osteoinduction in vitro. These results showed this novel hydrogel is an ideal candidate for applications in bone tissue regeneration and drug delivery.
Inflammation is a defense mechanism associated with a wide range of diseases. Celastrol is a small molecule isolated from traditional Chinese medicine with potent anti-inflammation activity. In this study, we established an integrated quantitative proteomics strategy to investigate the acute response to celastrol treatment in a rat macrophage cell line challenged with lipopolysaccharide (LPS). Both stable-isotopic based non-targeted quantitative profiling and PRM-based targeted quantitation methods were employed. Dimethyl-labeling based non-targeted profiling revealed 28 and 52 proteins that significantly up- and down-regulated by celastrol. Bioinformatics analysis pinpoint key signaling pathways affected. Seven proteins were selected for examining their time-dependent regulatory pattern in response to celastrol using targeted PRM quantitation. The abundance of mRNA at multiple time-points of selected proteins was also examined. Celastrol induced an acute response of selected key transcriptional factors in terms of mRNA or protein abundance within one hour. Interestingly, regulatory trend of mRNA and protein abundance suggested a novel dual mechanism of celastrol in the terms of acute anti-inflammation. The integrated quantitative proteomic strategy established in this study constitutes an efficient workflow to characterize key components and their time-dependent regulatory pattern for monitoring drug response.
Fe-based compounds with good environmental friendliness and high reversible capacity have attracted considerable attention as anode for lithium-ion batteries. But, similar to other transition metal oxides (TMOs), it is also affected by large volume changes and inferior kinetics during redox reactions, resulting in the destruction of the crystal structure and poor electrochemical performance. Here, Fe3O4/C nanospheres anchored on the two-dimensional graphene oxide as precursors are phosphated and sintered to build the multiphasic nanocomposite. XRD results confirmed the multiphasic nanocomposite composed of Fe2O3, Fe3O4 and Fe3PO7, which will facilitate the Li+ diffusion. And the carbonaceous matrix will buffer the volume changes and enhance electron conduction. Consequently, the multiphasic Fe-based anode delivers a large specific capacity of 1086 mAh/g with a high initial Coulombic efficiency of 87% at 0.1 C. It also has excellent cycling stability and rate property, maintaining a capacity retention of ~87% after 300 cycles and a high reversible capacity of 632 mAh/g at 10 C. The proposed multiphasic structure offers a new insight into improving the electrochemical properties of TMO-based anodes for advanced alkali-ion batteries.