Search

The biggest challenge is to develop a low cost and readily available catalyst to replace expensive commercial Pt/C for efficient electrochemical oxygen reduction reaction (ORR). In this research, closo-[B12H12]2− and 1,10-phenanthroline-iron complexes were introduced into the porous metal-organic framework by impregnation method, and further annealing treatment achieved the successful anchoring of single-atom-Fe in B-doped CN Matrix (FeN4CB). The ORR activity of FeN4CB is comparable to the widely used commercial 20 wt% Pt/C. Where the half-wave potential (E1/2) in alkaline medium up to 0.84 V, and even in the face of challenging ORR in acidic medium, the E1/2 of ORR driven by FeN4CB is still as high as 0.81 V. When FeN4CB was used as air cathode, the open circuit voltage of Zn-air battery reaches 1.435 V, and the power density and specific capacity are as high as 177 mW cm−2 and 800 mAh gZn−1 (theoretical value: 820 mAh gZn−1), respectively. The dazzling point of FeN4CB also appears in the high ORR stability, whether in alkaline or acidic media, E1/2 and limiting current density are still close to the initial value after 5000 times cycles. After continuously running the charge-discharge test for 220 h, the charge voltage and discharge voltage of the rechargeable zinc-air battery with FeN4CB as the air cathode maintained the initial state. Density functional theory calculations reveals that introducing B atom to Fe–N4–C can adjust the electronic structure to easily break O = O bond and significantly reduce the energy barrier of the rate-determining step resulting in an improved ORR activity.

The latissimus dorsi muscle (LDM) flap has been widely accepted as the best choice for subtotal or total scalp reconstruction. Because of the unique anatomic and functional features of scalp, ulcerations formation would occur after reconstructive surgeries. in this study, we are presenting a patient with a large scalp defect successfully reconstructed by a latissimus dorsi muscle free flap. Ulcerations with skull exposure formed on the transplanted flap after the first surgery. They were subsequently repaired by flap recycling and tissue expansion techniques. An excellent reconstructive outcome was achieved at the 30-month follow-up after the last surgery and no further complication was found. This clinical report highlights the possibility of ulcer formation after scalp reconstructive surgeries and supports the use of recycle flaps and tissue expanders to manage postoperative ulcerations after latissimus dorsi muscle free flap transplantation.

Perylene diimide derivatives (PDIs) are suitable ECL luminophore candidates with low triggering potentials and strong ECL signals for fundamental studies and practical applications. However, PDIs tend to aggregate, which affects their optical properties and limits their application in bio-imaging and bio-sensing fields. In this study, an ECL sensor is fabricated based on the layer-by-layer (LBL) assembly of N, N-bis(phosphonomethyl)-3,4,9,10-perylene diimide (PMPDI) and Zr

Electrochemical nitrate reduction reaction (NIRR) driven by sustainable energy is not only expected to realize the green production of ammonia under ambient conditions, but also a promising way to purify nitrate wastewater. The ammonia yield rate and Faradaic efficiency of NIRR catalyzed by Pd10Cu/BCN constructed with structural constraints and pre-embedded reducing agent strategies were as high as 102,153 μg h

Degrading health-threatening organic pollutants (HTOPs) in water systems through advanced oxidation processes (AOPs) is an effective way to treat environmental wastewater; however, such processes require advanced catalysts. This study combined complexation effects and structural confinement strategies to rapidly prepare Co2+-isolated metal–organic framework polymers and utilized a thermal treatment process to achieve the efficient anchoring of atom-dispersed Co in a boron–carbon-nitrogen matrix (denoted as SACoN/BCN), which can improve the utilization of Co catalytic sites. SACoN/BCN effectively activated peroxymonosulfate (PMS), with the ratio and mineralization rate of sulfamethazine (SMT) removed by degradation within 40 min reached 95.2 % and 70.0 %, respectively. Radical inhibition experiments and electron paramagnetic resonance (EPR) tests showed that 1O2 generated from SACoN/BCN-activated PMS was the key reactive oxygen species that promoted HTOP degradation. Density functional theory calculations revealed that, following the introduction of electron-deficient B heteroatoms, electrons in PMS will be injected into SACoN/BCN, thereby realizing strong adsorption and further activation of PMS. The cytotoxicity of SACoN/BCN is almost negligible because of the chemical bonding (or entrapment) of Co atoms in the inorganic boron–carbon-nitrogen matrix, thereby preventing Co from forming mobile CoII ions in the aqueous system. This research provides information for advanced catalysts for the removal of HTOPs and experimental and theoretical inspiration for the preparation of single-atom catalysts for advanced oxidation processes and the mechanism of PMS activation.

Hypercrosslinked pyrrole was synthesized via the Friedel–Crafts reaction and then carbonized to obtain urchin-like nitrogen-doped carbon (UNC). Ultrasmall iron oxide nanoparticles were then supported on UNC, and the composite was used to prepare an electrochemical sensor for detecting uric acid (UA) in human urine. FexOy/UNC was characterized and analyzed via scanning electron microscopy, transmission electron microscopy, energy dispersive spectrometry, X-ray diffraction, and X-ray photoelectron spectroscopy. A glassy carbon electrode (GCE) modified with FexOy/UNC was used as an electrochemical sensor to effectively identify UA. The electrochemical behavior of the FexOy/UNC-based UA sensor was studied using differential pulse stripping voltammetry, and the optimal conditions were determined by changing the amount of FexOy/UNC, pH of the buffer solution, deposition potential, and deposition time. Under optimal conditions, the FexOy/UNC-based electrochemical sensor detected UA in the range of 2–200 μM, where the limit of detection (LOD) for UA was 0.29 μM. Anti-interference experiments were performed, and the sensor was applied to the actual analysis of human urine samples. Urea, glucose, ascorbic acid, and many cations and anions present at 100-fold concentrations relative to UA did not strongly interfere with the response of the sensor to UA. The FexOy/UNC electrochemical sensor has high sensitivity and selectivity for uric acid in human urine samples and can be used for actual clinical testing of UA in urine.

As phosphate is one of the key causes of water eutrophication, its removal from aquatic ecosystems is essential. Adsorption methods have been widely used to remove phosphate from water bodies. However, most of the adsorbents are unstable and difficult to separate from solution. In this paper, we used a simple electrospinning method to prepare a new, well-dispersed, lanthanum (La)-based porous polyacrylonitrile nanofiber (LPS) with more active sites, which improve its phosphate removal efficiency. The maximum phosphate adsorption capacity on LPS was 218.5 mg P/g (La) (50.4 mg P/g). After complete adsorption, the P/La molar ratio on LPS was 0.98. After 48 h of oscillation, the leakage of La from LPS in deionized water was only 74 μg/L, effectively ruling out secondary pollution of the water-body. Moreover, unlike most adsorbents, LPS has the advantage that it can be readily isolated from water. After treatment with LPS, the total phosphorus (TP) of a water sample from Yangzonghai Lake (Yunnan, China) was reduced to 4.2 μg/L, a value lower than the concentration threshold of eutrophication (10 μg/L) set by the United States Environmental Protection Agency (USEPA) and the first category of the surface water environmental quality standard (10 μg/L) set by China for lakes and reservoirs.