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With the increase of diabetics, the incidence of diabetic wound, a common complication of diabetes, rapidly grows in clinical. Meanwhile, the high recurrence rate and mortality of diabetic wound make its treatment still a great challenge. Here, we design a M2 macrophage exosome loaded multifunctional hydrogel as the diabetic wound dressing. The combined injectable, self-healing, and tissue-adhesive properties of this hydrogel make it form a protective barrier covering the wound timely to stop bleeding quickly and provide a good healing condition for the wound. Then, the continuous releasing of M2 macrophage exosome is able to promote the angiogenesis in wound, therefore accelerating the diabetic wound healing.

The construction of internal electric field (IEF) is usually considered an effective strategy to enhance photocatalytic efficiency because of its significant role in photo-induced carrier separation. Herein, we report a novel method to synthesize phosphorus-doped (P-doped) MoS2/g-C3N4 layer-by-layer composite, which could expose more active sites and generate a strong interaction by forming Mo-N bonds for photocatalytic sterilization. It is experimentally and theoretically confirmed that P-doped MoS2/g-C3N4 heterojunctions not only generate a dual-IEF to drive charge migration, but also facilitate spatially separated redox sites to further promote the separation of photo-induced carrier. The optimized P-doped MoS2/g-C3N4 layered heterojunction exhibits high photocatalytic sterilization efficiency (99.99%) towards E. coli under visible-light irradiation, which is remarkably higher compared with those of P-doped g-C3N4 (44.73%) and P-doped MoS2 (61.69%), respectively. This research will offer a novel method of designing and synthesizing layered composite photocatalyst with a dual-IEF for effective photocatalytic sterilization.

ZnxCd1-xS is a prospective photocatalyst with wide visible-light absorption up to 500 nm, but its stability and activity are still facing huge challenges. Herein, L-Cysteine capped Mo2C (L-Mo2C) nanoplates were used to anchor Zn2+/Cd2+ to in-situ grow Zn0.67Cd0.33S nanomaterial for constructing a highly efficient and robust L-Mo2C/Zn0.67Cd0.33S heterojunction through intimate Mo-S covalent bonds for photocatalytic hydrogen evolution reaction (HER). This work not only suppresses the photo-corrosion of Zn0.67Cd0.33S nanomaterial by the construction of strong L-Mo2C/Zn0.67Cd0.33S Schottky heterojunction but also greatly improves the charge transfer efficiency by generating a strong internal electric field. As a result, the optimized L-Mo2C/Zn0.67Cd0.33S-5 heterojunction exhibits an enhanced HER rate of 34.66 mmol h−1 g−1 without an obvious decrease for continuous 24 h under visible irradiation, which is 4.8 times and 1.23 times than that of pristine Zn0.67Cd0.33S and uncapped Mo2C/Zn0.67Cd0.33S-5. This research highlights the role of Mo2C in photocatalytic HER, which provides a novel method to suppress the photo-corrosion of Zn0.67Cd0.33S-based composite.

Transition metal phosphides have shown Pt-like hydrogen evolution reaction (HER) activity in acid and alkaline solution, while their HER performance in neutral-pH is really poor owing to the high resistance and inefficient mass transfer in neutral-pH electrolyte. In this work, the well-arranged core/shell PSS-PPy/Ni-Co-P growing on Cu foil, in which Ni-Co-P is the core and the mixed polymer of pyrrole and sodium polystyrene sulfonate is the shell, has been demonstrated to be a highly efficient electrocatalyst for HER in neutral-pH electrolyte. The PSS-PPy/Ni-Co-P/CF self-supporting electrode was easily synthesized by electrodeposition and chemical deposition at room temperature. According to the experiment and DFT calculation results, PSS-PPy not only improves the conductivity and hydrophilicity of Ni-Co-P, but also optimizes the electronic structure of Ni-Co-P. Thus, the PSS-PPy/Ni-Co-P shows remarkable HER activity with only overpotential of 106 and 67 mV at the current density of 10 mA cm−2 in neutral-pH and alkaline electrolytes, respectively. Furthermore, PSS-PPy/Ni-Co-P has excellent stability in neutral-pH, alkaline electrolytes and even seawater. The current surface modification method directs us to design more low-cost, high-efficiency and stable electrocatalysts for HER in neutral-pH electrolyte.

We herein developed a facile method to prepare PEI grafted amino-functionalized graphene oxide nanosheets, which exhibit a high selectivity in capturing Cr(VI) contaminants from aqueous solutions with an ultrahigh adsorption capacity of 1185 mg/g and fast kinetics to reduce trace Cr(VI) concentrations below the allowed safe levels for drinking water defined by the WHO (0.05 mg/L) within 15 min in the presence of other coexistent ions. To the best of our knowledge, the adsorption capacity of the composites is highest among all PEI functional adsorbents reported so far. Furthermore, the cycle experiments indicated that the composites still exhibited excellent adsorption performance after 40 cycles. The adsorption-reduction mechanism of Cr(VI) on composites was further confirmed. Moreover, the separation performance of the composites was further improved by introducing magnetic nanoparticles on the surface of the composites. Finally, the composites were successfully utilized in dealing with the actual industrial effluent.

The notorious rapid recombination of photoinduced electron-hole limits the further application of polymeric carbon nitride (PCN) based photocatalysts. Face-to-face heterojunction composed of dissimilar 2D nanomaterials has been explored as a feasible way to facilitate the charge separation of PCN at the atomically well-defined hetero-interface. However, the conventional exfoliation-assembling process is tedious and time-consuming. Herein, a 2D/2D face-to-face heterojunction (MCN) has been constructed between sulfur (S)-doped polymeric carbon nitride nanosheets (SCN) and ultrathin molybdenum disulfide (MoS2) via a facile hydrothermal-polymerization method to overcome the recombination of photoinduced electron-hole pairs. The as-prepared MCN face-to-face heterojunction facilitated charge transport for the intimate interface contact and enhanced the separation of charge carriers, thus exhibiting high H2 evolution activity (2120 μmol h−1 g−1) without any other co-catalyst and high efficient degradation of dye. This work provides a facile protocol for synthesis of 2D/2D carbon nitride based photocatalysts towards future energy technology innovation.

N doped and B/N codoped TiO2 photocatalysts were synthesized by liquid phase precipitation combined with solid phase thermal decomposition method. For comparison, the same method was also used to prepare undoped TiO2 samples. The prepared catalysts were characterized using various techniques including XRD, BET, FT-IR, UV–vis DRS, XPS, SEM and Raman spectroscopy. BET results showed that 300B-N/TiO2 sample has higher BET surface area than undoped TiO2 and N-TiO2 samples. XPS analysis indicated that the B atoms mainly occupy the interstitial position of the TiO2. The photocatalytic performance of prepared undoped and doped TiO2 catalysts was evaluated under simulated sunlight irradiation by employing flumequine (FLU) as a target compound. The photocatalytic performance of TiO2 catalyst can be obviously enhanced by B/N codoping. In addition, B/N codoped TiO2 catalysts exhibit excellent cycling stability. The photocatalytic activity remained 90.1% for 300B-N/TiO2 after four repeated runs. The scavenger study shows that the main reactive species in the photocatalytic degradation process of FLU were superoxide radical (O2 −) and photogenerated electrons (e−). Based on detected degradation intermediates of FLU, three possible degradation pathways for FLU were proposed. The degradation of FLU occurs mainly by means of hydroxyl addition and subsequent demethylation and decarboxylation reactions, substitution of fluorine atom by hydroxyl and ring opening of quinolone ring. This work offers a simple method for fabrication of B/N codoped TiO2 photocatalysts, which will be effective in the removal of fluoroquinolones (FQs) in real wastewater.