Search

Developing highly efficient electrocatalysts for selective glycerol oxidation reaction (GOR) is crucial to implement biomass valorization and to advance the energy conversion efficiency of glycerol fuel cells. Herein, a hybrid alkali-acid direct glycerol fuel cell (DGFC) that can not only deliver a high power density but also enable glycerol valorization conversion is demonstrated. Such double-benefits electrochemical device is implemented by in situ growth of FeCoNiCrMnS 2 nanoparticles on carbon cloth (FeCoNiCrMnS 2 /CC) as anode, which exhibits high activity and selectivity for GOR with low overpotential and high Faradaic efficiency toward the formate product. Based on the results of finite element method simulations of element distribution on FeCoNiCrMnS 2 , the electrocatalytic sites was investigate by density functional theory in conjunction with Monte Carlo and machine learning simulations and confirmed that the desired catalytic properties primarily originate from the Ni and Co sites, while Cr and Mn optimized the electronic structure of these sites. The as-developed DGFC can release a maximum peak power density of 50.1 mW cm−2 and stably generate formate with high selectivity. The present work may inspire to contrive the newly advanced energy device and provide fresh impetus for the development of newly high-entropy materials for a variety of application. [Display omitted] • High-entropy alloy electrocatalysts of FeCoNiCrMnS 2 is developed for glycerol oxidation • The hybrid acid/alkali DGFC is proposed to simultaneously produce electricity and upgrade glycerol • The fuel cell can produce formate with an FE of exceeding 90 % and release a peak power density of 50.1 mW cm−2 • Combining DFT with MC and ML simulations unveil the crucial role of multiple elements in electrocatalysis [ABSTRACT FROM AUTHOR]

Exploring high-activity electrocatalysts for water electrolysis is a pivotal field of hot research as hydrogen is a very promising renewable energy source and bountiful in supply. Understanding the structure–composition–property relationships is the key for engineering improved electrocatalysts. We herein report a rational design on Ru-RuO 2 hybrid nanoparticles decorating carbon nanotubes composites electrocatalysts (Ru-RuO 2 /CNT), which shows impressively high activity toward hydrogen/oxygen evolution reaction (HER/OER) in all pH aqueous electrolytes. The Ru-RuO 2 /CNT, as an OER catalyst, requires ultralow overpotentials of 0.18 V, 0.27 V and 0.21 V to drive the current density of 10 mA cm−2 in acidic, neutral and alkaline media, respectively. Meanwhile, the catalyst also exhibits superior HER activity with the current density of 10 mA cm−2 at −0.063 V, −0.048 V and −0.012 V in acidic, neutral and alkaline media, respectively. Systematic characterizations and comprehensive electrochemical studies coupling with theoretical calculations verify that Ru favorably works with RuO 2 and CNT to synergistically contribute such highly desirable electrocatalytic activity. The bifunctional catalytic properties, in conjunction with its pH-universal compatibility, inspire us to an asymmetric-electrolyte electrolyzer was set up, which can harvest the electrochemical neutralization energy with implementing electrolysis H 2 generation with a current density of 10 mA cm−2 at an applied voltage of 0.73 V. The as-developed asymmetric-electrolyte electrolyzer, by coupling high-activity but not too expensive electrocatalysts with optimizing the catalytic efficiency in their favorable electrolyte, potentially provides an environmental-friend and energy-saving avenue for the future electrolysis H 2 generation. Image 1 • Bifunctional electrocatalysts for All-pH-electrolyte HER and OER. • High catalytic activity, good durability, and low cost. • Electrochemical neutralization energy was harvested for assisting electrolysis H 2 generation. • Water electrolysis in an asymmetric-electrolyte electrolyzer was implemented within 0.73 V. [ABSTRACT FROM AUTHOR]

Abstract We here report the fabrication of a core-shell WO 3 @ZnIn 2 S 4 heterostructure by an interfacial seeding growth strategy, which is implemented by direct growth of ZnIn 2 S 4 nanosheets on the surface of WO 3 nanorods with forming a strong electronic interaction between two semiconductors that are beneficial for promoting the interfacial charge transfer. Systematic studies demonstrate that the WO 3 @ZnIn 2 S 4 nanohybrids hold superior performance for photocatalytic hydrogen generation under visible light irradiation with a production rate of 3900 μmol g−1 h−1. This work provides an effective approach to construct the direct Z-scheme photocatalytic systems for efficient photocatalytic hydrogen evolution, which would be significant for the design of more direct Z-scheme system for various photocatalytic applications. [ABSTRACT FROM AUTHOR]

Exploring high-activity electrocatalyst for oxygen reduction reaction (ORR) is of great significance for a variety of renewable energy conversion and storage technologies. Herein, we report a template-free, economic and environment-friendly strategy for scalable synthesis of N-doped hierarchical porous carbon nanosheets (N-HPCNSs) with biomass water lettuces as carbon precursor. The N-HPCNSs were demonstrated to possess three dimensional (3D) hierarchical porous structures with a high surface area and uniform N-doping. Systematic electrochemical study revealed that the N-HPCNSs not only hold numerous active sites but also manifest high intrinsic activity for each of the active sites toward ORR in pH-universal electrolyte of alkali, acid and neutral. With the N-HPCNSs as cathode electrocatalyst, three types of home-made fuel cells were set up that run in alkaline, acidic and neutral medium, i.e. , Zn-air alkaline fuel cell, direct methanol fuel cell, and microbial fuel cell, respectively, further demonstrating its potential to replace the high-cost Pt-based electrocatalysts for practical applications. Owning to the multiple attracting features, including high catalytic activity, good durability, low cost, and scalable production, the as-developed pH-universal N-HPCNS electrocatalysts may open a promising avenue for developing the next-generation cathode electrocatalysts for fuel cells of practical significance. [ABSTRACT FROM AUTHOR]

Transition metal dichalcogenide is a promising candidate for platinum-free electrocatalysts in renewable energy applications. In this work, we developed an aerosol processing method for facile and green synthesis of reduced graphene oxide (rGO)/tungsten disulfide (WS 2 )/tungsten trioxide (WO 3 ) ternary nanohybrids. The resulting material has a spherical structure constructed by crumpled graphene and WS 2 /WO 3 nanorods. The crumpled graphene/WS 2 /WO 3 (CGTH) catalyst showed a superior electrocatalytic activity in the hydrogen evolution reaction (HER), with a Tafel slope of 37 mV/dec and an onset potential of 96 mV. Compared with reported MoS 2 /WS 2 -based electrocatalysts, this hybrid material shows one of the highest catalytic activities in HER. The environmentally-friendly synthesis and outstanding performance suggest a great potential of CGTH as noble metal-free electrocatalysts in water splitting. [ABSTRACT FROM AUTHOR]

Cu-based composites with different compositions and construction can seriously influence its electrocatalytic performance toward CO 2 reduction reaction (CO 2 RR). Herein, we report a microwave-assistant route to prepare Cu nanoparticles decorating reduced graphene oxide (CuNPs/rGO) nanohybrids, which are characterized by a variety of techniques, demonstrating that Cu nanoparticles coupling with Cu x O nanoparticles were uniformly anchored on the surface of rGO, as well as the existence of grain boundaries. The CuNPs/rGO composites are studied as electrocatalyst for CO 2 RR and show a favorable electrocatalytic activity toward CO 2 RR with an onset potential of −0.9 V, corresponding to about only 190 mv overpotential for CO generation. Besides with a small amount of HCOOH (<5%), H 2 and CO are the main CO 2 reduction products with a tunable ratio of from 1.16:1 to 6.38:1 by changing the applied potentials. The gaseous products with various ratio of H 2 to CO can be potentially used as syngas to produce more valuable products in industry. This work demonstrates a simple, facile and effective way to improve the electrocatalytic CO 2 RR performance of Cu-based composites. [ABSTRACT FROM AUTHOR]

Sunlight provides us with enough renewable energy resource being potentially converted into heat for steam generation, residential water heating, desalination, and wastewater treatment, while the exploration of low-cost but high-efficiency photothermal materials still remains a grand challenge. We here reported a new Al-Ti-O nanostructure with tunable colors from gray to black, which couples the features of plasmonic effects in Al nanoparticles and high photoactivity in black TiO 2 , enabling the optimized black Al-Ti-O nanostructure shows a broad light absorption capability with almost covering 90.32% of solar spectrum. Inspiringly, the black Al-Ti-O hybrid were assembled into a microporous membrane that can naturally float on the surface of water for photothermal desalination application, manifesting a high efficiency of 77.52% for desalination under simulated solar light irradiance, as well as an outstanding durability upon continuous running. A solar seawater desalination system was designed and manufactured to demonstrate its potential for practical application, which can produce purified water with a rate of ~ 0.50 kg m −2 h −1 , or ~ 4 L m −2 day −1 , given that the effective sunshine time is 8 h per day under current solar irradiation (~ 820 W m −2 ). The numerous advantages in the present black Al-Ti-O hybrid, including high photothermal efficiency, viable scalable synthesis, and low cost, may build step stone for commercial solar desalination application. [ABSTRACT FROM AUTHOR]

Nanohybrids with hollow CoNiP nanoparticles decorating reduced graphene oxide (h-CoNiP/rGO) are prepared by a low-temperature phosphorization method. The h-CoNiP/rGO present favorable electrocatalytic advantages toward the oxygen evolution reaction (OER) in alkaline solution, including an onset potential of 1.44 V, a low overpotential of 280 mV at a current density of 10 mA cm − 2 , a small Tafel slope of 65.2 mV dec − 1 , and pretty good durability. The use of earth-abundant elements in a high-activity OER electrocatalyst may provide an effective way of advancing the development of full water splitting. [ABSTRACT FROM AUTHOR]

The daunting challenge in electrochemical conversion of CO 2 into carbon resource is to explore high-activity and high-selectivity electrocatalysts for CO 2 reduction reaction (CO 2 RR). Here, we report a water-bath route for tunable synthesis of a set of CuO nanostructures including nanowires (NWs), microsphere and nanoflake. The CuO NWs show a unique one-dimensional (1D) structure constructed by nanoparticles building block and manifest a significantly enhanced electrochemical surface area compared with the counterparts and the bulk CuO. Systematic electrochemical studies demonstrate the CuO NWs, as electrocatalyst of CO 2 RR, manifests a highly electrocatalytic activity, as demonstrated by reaching a current dentistry of 2 mA cm −2 at a relative low onset potential and delivering a catalytic current density of up to 100 mA cm −2 at −1.6 V. The nanoparticles assembled 1D structure provides a large amount of edge active sites and thus contributes to such a high electrocatalytic activity. Besides a small quantity of HCOOH, the major products of CO 2 RR are H 2 , CO, with tunable ratio of H 2 /CO in the range of 1.75:1 to 2.75:1 depending on the applied potential; such H 2 /CO mixture product are potentially used for the syngas that are key feedstocks to produce a variety of liquid fuels in industry. [ABSTRACT FROM AUTHOR]

A simple pyrolysis route has been developed for fabrication of nitrogen-doped carbon networks (N-C net) that not only features a large number of mesoporous structures, but also holds high specific surface area and excellent conductivity. The as-developed N-C net performs impressively toward electrocatalysis of oxygen reduction reaction (ORR) and CO 2 reduction reaction (CO 2 RR). For ORR in alkaline electrolyte, the N-C net manifests an initial potential of 0.95 V and half-wave potential of 0.86 V that are comparable to the benchmarked Pt/C catalysts. While for CO 2 RR, the N-C net shows a high selectivity for CO production with Faraday efficiency (FE) of as high as 95% and long-term stability. We further demonstrate the potential application of N-C net in electrochemical devices of zinc-air batteries (ZABs) and microbial CO 2 electrolysis cell (MEC), the former is capable of releasing a maximum power density of 141 mW cm-2, while the later shows capability for efficiently converting CO 2 into CO with the assistance of external voltage. We thus propose and set up an integrated proof-of-concept electrochemical device with ZABs driving MEC that can implement the feasibility of self-powered conversion of CO 2 to value-added CO. [Display omitted] • The N-doped carbon networks prepared by one-pot pyrolyzing ZIF-8 exhibited excellent electrocatalytic properties toward oxygen reaction reduction and CO 2 reduction. • Catalyzed by the cathodic bifunctional N-doped carbon networks, the Zn-air batteries and microbial CO 2 electrolysis cell with favorable performance were assembled in this work. • A coupled electrochemical device with ZABs driving MEC was firstly proposed and achieved self-powered conversion of CO 2 to value-added CO. [ABSTRACT FROM AUTHOR]

A novel Co 3 O 4 /N-doped porous carbon hybrid with dodecahedrons structure was synthesized by a facile, two-step, thermal transformation of a cobalt-based zeolitic imidazolate framework. Well-dispersed Co 3 O 4 nanoparticles were embedded in nitrogen-doped porous carbon networks, forming a unique nanopolyhedron. When tested as anode material for lithium-ion batteries, the hybrid exhibited superior electrochemical performance, including excellent rate capability of 560 mA h g −1 at 10 A g −1 which is close to 46% of the rate capacity at 100 mA g −1 , outstanding cycling stability with 91.7% capacity retention of the second cycle after 110 cycles, and considerably large discharge capacity of 1730 mA h g −1 at 100 mA g −1 . Moreover, the hybrid also showed enhanced electrocatalytic activity for electrochemical oxygen evolution from water splitting. [ABSTRACT FROM AUTHOR]