Rational design efficient transition metal-based electrocatalysts for oxygen evolution reaction (OER) is critical for water splitting. However, industrial water-alkali electrolysis requires large ...current densities at low overpotentials, always limited by intrinsic activity. Herein, we report hierarchical bimetal nitride/hydroxide (NiMoN/NiFe LDH) array as model catalyst, regulating the electronic states and tracking the relationship of structure-activity. As-activated NiMoN/NiFe LDH exhibits the industrially required current density of 1000 mA cm
at overpotential of 266 mV with 250 h stability for OER. Especially, in-situ electrochemical spectroscopic reveals that heterointerface facilitates dynamic structure evolution to optimize electronic structure. Operando electrochemical impedance spectroscopy implies accelerated OER kinetics and intermediate evolution due to fast charge transport. The OER mechanism is revealed by the combination of theoretical and experimental studies, indicating as-activated NiMoN/NiFe LDH follows lattice oxygen oxidation mechanism with accelerated kinetics. This work paves an avenue to develop efficient catalysts for industrial water electrolysis via tuning electronic states.
Biomimetic modified membranes for oil/water separations have attracted extensive attention in recent years. However, complex processing, low efficiency and severe oil fouling have always been the ...main obstacles to its application. To explore facile and green modification methods are urgently desired. Herein, we create a facile, high separation efficiency, energy conservation, eco-friendly, and anti-crude oil fouling superwettability membrane for oil/water separation. Hierarchical nanoparticles structures are developed on the surface of poly (vinylidene fluoride) (PVDF) microfiltration (MF) membranes by co-depositing proanthocyanidins (PC) and γ-aminopropyltriethoxysilane (APTES). The construction of hierarchical nanoparticles on the membrane surface bestows superhydrophilic and underwater superoleophobic functionality and excellent oil/water separation properties for addressing various oils. The oil rejections of the modified membrane are all above 99.5%, and it has superior crude oil fouling-tolerant performance with good pH, chemical and mechanical stability and salt resistance. This modification strategy can be applied to clean the oil-contaminated cotton cloth and non-woven fabrics. Thus, the applications of the proposed modified strategy include but not limited to oily wastewater treatment and self-cleaning clothing production.
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•Biomimetic nanoparticle-engineered membranes was designed for oil/water separation.•Proanthocyanidins (PC) and γ-aminopropyltriethoxysilane (APTES) were co-deposited.•The novel membrane possessed superhydrophilicity and underwater superoleophobicity.•The membrane had superior crude oil fouling-tolerant and self-cleaning ability.
The all‐inorganic CsPbBr3 perovskite solar cell (PSC) is a promising solution to balance the high efficiency and poor stability of state‐of‐the‐art organic–inorganic PSCs. Setting inorganic ...hole‐transporting layers at the perovskite/electrode interface decreases charge carrier recombination without sacrificing superiority in air. Now, M‐substituted, p‐type inorganic Cu(Cr,M)O2 (M=Ba2+, Ca2+, or Ni2+) nanocrystals with enhanced hole‐transporting characteristics by increasing interstitial oxygen effectively extract holes from perovskite. The all‐inorganic CsPbBr3 PSC with a device structure of FTO/c‐TiO2/m‐TiO2/CsPbBr3/Cu(Cr,M)O2/carbon achieves an efficiency up to 10.18 % and it increases to 10.79 % by doping Sm3+ ions into perovskite halide, which is much higher than 7.39 % for the hole‐free device. The unencapsulated Cu(Cr,Ba)O2‐based PSC presents a remarkable stability in air in either 80 % humidity over 60 days or 80 °C conditions over 40 days or light illumination for 7 days.
Cu(Cr,M)O2 nanocrystals with hole boosting by increasing the amount of interstitial oxygen enables them to be promising HTMs for all‐inorganic CsPbBr3 perovskite solar cells. The optimized device with Cu(Cr,Ba)O2 achieves a record efficiency as high as 10.79 %.
•The thermodynamic and thermo-economic models of SORC and DORC are built.•The thermodynamic and thermo-economic performances are optimized and compared.•The DORC can increase power output and show ...better thermo-economic performance.
The goal of this paper is to study and evaluate the thermodynamic and the thermo-economic performance of dual-pressure and single pressure evaporation organic Rankine cycle (DORC and SORC) using isobutane as the working fluid. The effects of the two-stage pressures and the heat source inlet temperature on the system performances have been investigated. Then the performance comparisons between SORC and DORC have been conducted at the optimized condition. Results show that the DORC yields more net power than the SORC when the heat source temperature is between 100 and 177.2 °C, and the net power output gains of the DORC are higher at lower heat source temperature. The DORC no longer has the performance advantage as the heat source temperature is above 177.2 °C. The thermo-economic evaluations show that the optimized electricity production cost (EPC) decreases as the heat source temperature rises. Furthermore, optimized EPC of SORC and DORC are nearly equal at the same heat source temperature. For the heat source temperature of 100–177.2 °C, the DORC can significantly increase the net power output, but the thermo-economic performance of DORC is not reduced by system complexity compared to the SORC.
Moisture is the worst enemy for state‐of‐the‐art perovskite solar cells (PSCs). However, the flowing water vapor within nanoporous carbonaceous materials can create potentials. Therefore, it is a ...challenge to integrate water vapor and solar energies into a single PSC device. We demonstrate herein all‐inorganic cesium lead bromide (CsPbBr3) solar cells tailored with carbon electrodes to simultaneously harvest solar and water‐vapor energy. Upon interfacial modification and plasma treatment, the bifunctional PSCs yield a maximum power conversion efficiency up to 9.43 % under one sun irradiation according to photoelectric conversion principle and a power output of 0.158 μW with voltage of 0.35 V and current of 0.45 μA in 80 % relative humidity through the flowing potentials at the carbon/water interface. The initial efficiency is only reduced by 2 % on exposing the inorganic PSC with 80 % humidity over 40 days. The successful realization of physical proof‐of‐concept multi‐energy integrated solar cells provides new opportunities of maximizing overall power output.
Rising damp: An all‐inorganic perovskite solar cell backed by a tailored carbon electrode is made to simultaneously harvest solar and water‐vapor energies, in that the water vapor within nanoporous carbonaceous materials can generate potentials, yielding a maximum power conversion efficiency (PCE) of 9.43 % under one sun irradiation and a power output of 0.158 μW with a voltage of 0.35 V and a current of 0.45 μA in 80 % relative humidity.
We report a novel nanophotosensitizer
via
one-step covalent assembly of dopamine and genipin. This is the first report unveiling the photodynamic effect of dopamine-based materials. These ...nanophotosensitizers can also act as pH-responsive drug nanocarriers
via
a catechol-boronate linkage, thus achieving combined PDT and chemotherapy for highly efficient cancer treatment.
A covalently assembled dopamine nanoparticle is constructed to serve as an intrinsic photosensitizer and pH-responsive drug nanocarrier for combined PDT and chemotherapy.
Anchoring vertically grown CoMn-LDH nanosheets on 3D hierarchical porous N,P co-doped graphene aerogel frameworks forms an sufficient bifunctional oxygen electrocatalyst for rechargeable zinc-air ...battery.
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Exploiting the low-cost and high-efficiency bifunctional oxygen electrocatalysts to substitute platinum-group metals is highly desirable but challenging for energy storage/conversion technologies. Herein, we develop a combined gelation/self-assemble/freeze drying process to fabricate a free-standing porous architectures through vertical anchoring two-dimensional (2D) CoMn-LDH nanosheets on three-dimensional (3D) hierarchical N,P co-doped graphene aerogels (NPGA) framework. This unique configuration endows CoMn-LDH/NPGA outstanding catalytic activity toward both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) with a potential difference of ca. 0.72 V between the OER potential at 10 mA cm−2 and the ORR potential at −3 mA cm−2, which is comparable to commercial Pt/C + IrO2 benchmarks, and therefore renders the CoMn-LDH/NPGA assembled zinc-air battery a superior rechargeable performance and cycling stability. In-depth structure-to-property correlation indicates that the prominent bifunctional activity of CoMn-LDH/NPGA are ascribed to large electrochemical active surface area, the rapid mass/charge transfers, the increased exposure and full utilization of active sites originated from the synergistic effect between the uniformly dispersed 2D CoMn-LDH nanosheets and the 3D hierarchical porous NPGA framework.
Here, we present a proactive fouling prevention mechanism that endows superhydrophilic membranes with antifouling capability against migratory viscous crude oil fouling. By simulating the ...hierarchical architecture/chemical composition of a dahlia leaf, a membrane surface is decorated with wrinkled-pattern microparticles, exhibiting a unique proactive fouling prevention mechanism based on a synergistic hydration layer/steric hindrance. The density functional theory and physicochemical characterizations demonstrate that the main chains of the microparticles are bent towards Fe
through coordination interactions to create nanoscale wrinkled patterns on smooth microparticle surfaces. Nanoscale wrinkled patterns reduce the surface roughness and increase the contact area between the membrane surface and water molecules, expanding the steric hindrance between the oil molecules and membrane surface. Molecular dynamic simulations reveal that the water-molecule densities and strengths of the hydrogen bonds are higher near the resultant membrane surface. With this concept, we can successfully inhibit the initial adhesion, migration, and deposition of oil, regardless of the viscosity, on the membrane surface and achieve migratory viscous crude oil antifouling. This research on the PFP mechanism opens pathways to realize superwettable materials for diverse applications in fields related to the environment, energy, health, and beyond.
Organophosphate flame retardants (OPFRs) have been detected in various environmental matrices and have been identified as emerging contaminants (EC). Given the adverse influence of OPFRs, many ...researchers have focused on the absorption, bioaccumulation, metabolism, and internal exposure processes of OPFRs in animals and humans. This paper first reviews the evolution of various types of flame retardants (FRs) and the environmental pollution of OPFRs, the different absorption pathways of OPFRs by animals and humans (such as inhalation, ingestion, skin absorption and absorption), and then summarizes the environmental impacts of OPFRs, including their biological toxicity, bioaccumulation, persistence, migration, endocrine disruption and carcinogenicity. Based on limited available data and results, this study also summarizes the bioaccumulation and biomagnification potential of OPFRs in different types of biological and food nets. In addition, a new governance idea for the replacement of existing OPFRs from the source is proposed, seeking environmentally friendly alternatives to OPFRs in order to provide new ideas and theoretical guidance for the removal of OPFRs.
To explore the optimum fermentation conditions for tobacco leaves and also screen the microbiota and metabolites that are beneficial for fermentation.
Tobacco leaves were fermented at 25 °C, 35 °C, ...and 45 °C for 2, 4, and 6 weeks, respectively. For identification of the best fermentation temperature, physicochemical properties and sensory quality of fermented tobacco were investigated. Subsequently, based on the appropriate temperature, 16 s rRNA sequencing and metabolomics analysis of tobacco were performed to monitor the change of microbes and metabolites during fermentation process (from 2 to 6 weeks).
Sensory quality analysis indicated that fermentation at 45 °C for 6 weeks represented the optimum condition. Metabolomics analysis showed that a total of 415 metabolites were annotated. The increase of fermentation period led to significant changes of metabolites. Results revealed an increase in concentration of L-phenylalanine and sphingosine as well as decreased concentration of betaine and phytosphingosine with the prolongation of fermentation period (2 to 6 weeks). Distinct changes in the microbiota were also observed with prolongation of the fermentation time. Results revealed that Pseudomonas, Pantoea, and Burkholderia were dominant bacteria in fermentation at 45 °C for 6 weeks. With the extension of the fermentation time, the abundance of Pseudomonas increased, while that of Sphingomonas and Methylobacterium decreased. Furthermore, microbiota profiles were tightly relevant to the altered metabolites, especially compounds involved in the sphingolipid metabolism.
Suitable fermentation conditions were 45 °C for 6 weeks; phytosphingosine and sphingosine might affect tobacco fermentation via the sphingolipid metabolism pathway. This study provides a theoretical basis for guiding tobacco fermentation and gives insights into reducing harmful substances during tobacco fermentation.
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