Electrocatalytic Decomposition Research Articles

Heterojunction photoelectric device with fast response speed and low power consumption composed of WSSe and AlN

Through the accurate calculation of density functional theory, reveal the excellent photoelectric properties of the AlN/WSSe and WSSe/AlN heterojunction. Especially, the hole mobility of the AlN/WSSe heterojunction is as high as 3919 cm2Vs-1in armchair direction, and the hole mobility of the WSSe/AlN heterojunction is as high as 4422 cm2Vs-1in the zigzag direction. Interestingly, when two H atoms are adsorbed in the WSSe surface, the Gibbs free energy change are -0.093 eV and -0.984 eV, which tends to zero, which can promote the spontaneous reaction of electrocatalytic water decomposition to produce H2. In addition, the AlN/WSSe heterojunction exhibits significant photoelectric effect photocurrent (1.15 a02/photon) in the armchair direction and the heterojunctions have lower threshold voltage (1.5 V), that indicate the AlN/WSSe and WSSe/AlN heterojunction have great application prospect in manufacturing high-performance optoelectronic devices with fast response and low power consumption.

Controlled synthesis of Sn doped Cu–Ni3S2 on Ni foam as efficient electrocatalyst for urea oxidation reaction and oxygen evolution reaction

Hydrogen production technology by urea-assisted electrocatalytic water decomposition has become one of the important means to alleviate carbon emissions and water pollution. In this paper, we first doped Sn and Cu element into the Ni3S2 material by hydrothermal method on the Ni foam support. This Cu–Sn–Ni3S2 material exhibits superior urea (potential of 1.42 V at 100 mA cm−2) and water oxidation (potential of 1.63 V at 100 mA cm−2) properties, which is one of the best electrochemical performance reported up to now. Analysis of experiment demonstrate that the increase in catalytic performance is assigned to faster charge transfer, more exposure of reaction centres and smaller resistance owing to doping of Sn and Cu. Density functional theory (DFT) analysis demonstrates that introduction of Sn and Cu increases the adsorption energy of urea and improves the conductivity of the Cu–Sn–Ni3S2 material, and the co-doping of the two changes the electron state density of the active site, thereby promoting the catalytic performance. This work provides insights into the development of efficient bifunctional electrodes for urea oxidation and oxygen evolution reaction through doping strategies.

Optimized Electrocatalytic Adsorption Degradation of Oilfield Produced Water Using New Dimension Stable Anode

AbstractIn this study, we synthesized a novel electrode for electrocatalytic adsorption by fabricating ACF‐TiO2 via the sol‐gel method and binding it with IrO2‐TaO2. The electrode's effectiveness in treating oilfield produced water (OPW) was evaluated using batch techniques. Comprehensive characterization, including scanning electron microscopy (SEM), energy‐dispersive spectrometry (EDS), Brunauer‐Emmett‐Teller (BET) analysis, and Fourier‐transform infrared (FTIR) spectroscopy, confirmed uniform TiO2 loading onto the ACF surface, preserving structural integrity. BET analysis indicated increased mesopore volume and enhanced organic adsorption capacity without compromising microporous structure. Additionally, FTIR analysis revealed the emergence of functional groups conducive to adsorption and catalytic reactions. Freundlich isotherms and pseudo‐first‐order kinetics best fit the adsorption data. Remarkably, even after five cycles, the electrode maintained high removal efficiencies for chemical oxygen demand (COD) and oil content at 91.35 % and 91.12 %, respectively. We further investigated the complex phenomena of material adsorption, electrochemical oxidation, and desorption during electrocatalytic adsorption, highlighting the importance of solid‐phase adsorption and liquid‐phase electrocatalytic oxidative decomposition in OPW treatment. Comparison with similar electrodes and DSA electrodes demonstrated the superior performance and practicality of the IrO2‐TaO2‐ACF(TiO2) electrode. Its cost‐effectiveness and regeneration method further enhance its applicability in real‐world scenarios, emphasizing its potential in water treatment.

Electrocatalytic Decomposition of Lithium Oxalate-Based Composite Microspheres as a Prelithiation Additive in Lithium-Ion Batteries.

In conventional lithium-ion batteries (LIBs), the active lithium from the lithium-containing cathode is consumed by the formation of a solid electrolyte interface (SEI) at the anode during the first charge, resulting in irreversible capacity loss. Prelithiation additives can provide additional active lithium to effectively compensate for lithium loss. Lithium oxalate is regarded as a promising ideal cathode prelithiation agent; however, the electrochemical decomposition of lithium oxalate is challenging. In this work, a hollow and porous composite microsphere was prepared using a mixture of lithium oxalate, Ketjen Black and transition metal oxide catalyst, and the formulation was optimized. Owing to the compositional and structural merits, the decomposition voltage of lithium oxalate in the microsphere was reduced to 3.93 V; when being used as an additive, there is no noticeable side effect on the performance of the cathode material. With 4.2% of such an additive, the first discharge capacity of the LiFePO4‖graphite full cell increases from 139.1 to 151.9 mAh g-1, and the coulombic efficiency increases from 88.1% to 96.3%; it also facilitates the formation of a superior SEI, leading to enhanced cycling stability. This work provides an optimized formula for developing an efficient prelithiation agent for LIBs.

Nanocage confined nitrogen-rich MOF-derived Co/CoN heterostructure for overall water splitting

Of great significance is the study towards replacing precious metal electrocatalysts with transition metal electrocatalysts for the electrocatalytic hydrogen evolution from water, regarding clean energy utilization. The precise design and engineering of catalysts at the nanoscale, with a focus on their structural and functional attributes, have garnered significant attention and research interest as pivotal approaches to optimizing their catalytic performance. Among those strategies, fabricating transition metals and their corresponding nitrides has lately gained extensive attentions for electrocatalytic water decomposition, because of their adjustable distribution of electrons. In this study, ZIF-67@MAT-6 precursor was formed by coating ZIF-67 with triazole ligand (MAT-6) based on ligand exchange strategy, followed by confining Co/CoN heterostructure nanoparticles in nitrogen-doped carbon nanocages upon heat treatment under nitrogen flow. The resulting electrocatalyst exhibited outstanding electrocatalytic performance for hydrogen and oxygen evolution reactions in alkaline media, with overpotentials of 115 mV and 290 mV to reach 10 mA·cm−2 in 1 M KOH electrolyte, respectively. In addition, the electrocatalyst showed great durability with only 2.16 % current decay during 24 h potentiostatic electrolysis for water decomposition. The density functional theory (DFT) theoretically supported that the accelerated interfacial charge transfer and promoted electrical conductivity were responsible for the remarkable electrocatalytic performance, caused by the synergic effect between the heterogeneous Co and CoN.

A self-supported porous NiMo electrocatalyst to boost the catalytic activity in the hydrogen evolution reaction.

To develop hydrogen energy production and address the issues of global warming, inexpensive, effective, and long-lasting transition metal-based electrocatalysts for the synthesis of hydrogen are crucial. Herein, a porous electrocatalyst NiMo/Ni/NF was successfully constructed by a two-step electrodeposition process, and was used in the hydrogen evolution reaction (HER) of electrocatalytic water decomposition. NiMo nanoparticles were coated on porous Ni/NF grown on nickel foam (NF), leading to a resilient porous structure with enhanced conductivity for efficient charge transfer, as well as distinctive three-dimensional channels for quick electrolyte diffusion and gas release. Notably, the low overpotential (42 mV) and fast kinetics (Tafel slope of 44 mV dec-1) at a current density of 10 mA cm-2 in 1.0 M KOH solution demonstrate the excellent HER activity of the electrode, which was superior to that of recently reported non-noble metal-based catalysts. Additionally, NiMo/Ni/NF showed extraordinary catalytic durability in stability tests at a current density of 10 mA cm-2 for 70 h. The porous structure catalyst and the electrodeposition-electrocatalysis technique examined in this study offer new approaches for the advancement of the electrocatalysis field because of these benefits.

Engineering hierarchical snowflake-like multi-metal selenide catalysts anchored on Ni foam for high-efficiency and stable overall water splitting.

The development of excellent bifunctional electrocatalysts is an effective way to promote the industrial application of electrolytic water. In this work, a free-standing W-doped cobalt selenide (W-CoSe300/NF) electrocatalyst with a snowflake-like structure supported on nickel foam was prepared by a hydrothermal-selenization strategy. Benefiting from the high specific surface area of the 3D snowflake-like structure and the regulation of tungsten doping on the electronic structure of the metal active center, W-CoSe300/NF shows remarkable electrocatalytic water decomposition performance. In 1.0 M KOH, the W-CoSe300/NF electrocatalyst achieved an efficient HER and OER at a current density of 50 mA cm-2 with overpotentials as low as 84 mV and 283 mV, respectively. More importantly, W-CoSe300/NF acts as both the anode and cathode of the electrolytic tank, requiring only a potential of 1.54 V to obtain 10 mA cm-2 and can operate continuously for more than 120 hours at this current density. This study proposes a new way for the design of high efficiency and affordable bifunctional electrocatalysts.

Interfacial engineering of RuO2 for electrocatalytic decomposition of Li2CO3 in Li–CO2/O2 battery

Li2CO3, the primary byproduct of Li–CO2/O2 batteries, is challenging to decompose electrochemically and its accumulation cause the short lifespan of the battery. Herein, we report strong interfacial interaction between the intimately interfaced ultrafine RuO2 and Co3O4 nanoparticles, which leads to transfer of electrons from Ru 4d orbital to Co 3d orbital via interfacial Ru–O–Co bridges. Such intense interaction is found to boost the adsorption of CO2 and O2 on the RuO2; more importantly, it can also effectively decrease the energy barrier for the rate determining step of decomposition of Li2CO3. Therefore, both the formation and decomposition kinetics of Li2CO3 during charge and discharge are efficiently enhanced on the Co3O4-interfaced RuO2 compared to the freestanding RuO2. Using such Co3O4-interfaced RuO2 as cathode catalyst, Li–CO2/O2 (V:V = 4:1) batteries depict an overpotential as low as 1.31 V and a cycling stability of 137 cycles under a constant capacity of 1000 mAh g−1, which is significantly better than that with only Co3O4 or RuO2; the enhanced decomposition kinetics of Li2CO3 is also confirmed by monitoring the release of CO2 using in-situ mass spectrum. This work emphasizes the role of interfacial oxygen bridges in enhancing electrocatalytic decomposition of Li2CO3.

Electrocatalytic Coenhancement of Bimetallic Polyphthalocyanine-Anchored Ru Nanoclusters Enabling Efficient Overall Water Splitting at Ampere-Level Current Densities.

Efficient electrocatalysts capable of operating continuously at industrial ampere-level current densities are crucial for large-scale applications of electrocatalytic water decomposition for hydrogen production. However, long-term industrial overall water splitting using a single electrocatalyst remains a major challenge. Here, bimetallic polyphthalocyanine (FeCoPPc)-anchored Ru nanoclusters, an innovative electrocatalyst comprising the hydrogen evolution reaction (HER) active Ru and the oxygen evolution reaction (OER) active FeCoPPc, engineered for efficient overall water splitting are demonstrated. By density functional theory calculations and systematic experiments, the electrocatalytic coenhancement effect resulting from unique charge redistribution, which synergistically boosts the HER activity of Ru and the OER activity of FeCoPPc by optimizing the adsorption energy of intermediates, is unveiled. As a result, even at a large current density of 2.0 A cm-2 , the catalyst exhibits low overpotentials of 220 and 308mV, respectively, for HER and OER. It exhibits excellent stability, requiring only 1.88V of cell voltage to achieve a current density of 2.0 A cm-2 in a 6.0m KOH electrolyte at 70°C, with a remarkable operational stability of over 100 h. This work provides a new electrocatalytic coenhancement strategy for the design and synthesis of electrocatalyst, paving the way for industrial-scale overall water splitting applications.

Construction of efficient hydrogen evolution catalyst and analysis of the influence of complexing agent type

In electrocatalytic water decomposition technology, particularly in alkaline solutions, hydrogen evolution with transition metal catalysts has received significant interest. In this study, an efficient HER electrocatalyst with nickel foam base was produced by electrodeposition. Compared with other catalysts, the synthesized CoMo@EDTA electrocatalyst showed significant electrocatalytic activity against HER in alkaline electrolytes. By changing the type of complexing agent, it is found that the overpotential is the lowest after adding EDTA-2Na in 1 mol/l NaOH solution. The overpotential of the CoMo@EDTA catalyst is 29 mV, When the current density is −10 mA/cm2, The outstanding HER performance of CoMo@EDTA electrocatalysts is mainly due to the interaction of molybdenum and cobalt and the effect of complexing agents. After the stability measurement for up to 6 h, the catalyst has a minimal overpotential loss, indicating that the catalyst has excellent stability. This work provides a useful pathway for the application of transition metals in hydrogen evolution electrocatalysts.

Preparation of Co/V bimetallic phosphide derived from MOFs and its application in electrocatalytic water decomposition

Rational design and development of electrocatalysts with low cost, abundant reserves, high efficiency and high stability are of great significance to the development of hydrogen economy. In this work, MOFs-derived Co/V phosphide bifunctional electrocatalysts (Co2VP-MOF@NF) are successfully fabricated on the nickel foam (NF) substrate. Due to the rich heterogeneous interface produced by in-situ phosphorization of CoV-MOF@NF and the large number of defects produced by alkali etching, the Co2VP-MOF@NF exhibits excellent electrocatalytic activity. The overpotential for HER (hydrogen evolution reaction) and OER (oxygen evolution reaction) is 80 mV and 265 mV at 10 mA cm−2, respectively. More importantly, only a decomposition voltage of 1.51 V is needed at 10 mA cm−2, and the electrolyser completed relatively conspicuous durability, maintaining the initial current density through 24 h persistent work. The methods of in situ phosphorization to form heterogeneous interfaces and alkali etching to form defects provide a reasonable strategy for the preparation of highly active electrocatalysts with excellent electrocatalytic performance.

Controlled synthesis of M (M = Cr, Cu, Zn and Fe)-NiCoP hybrid materials as environmentally friendly catalyst for seawater splitting

The consumption of non-renewable resources has determined that the exploration and utilization of pollution free energy has been a hot research subject in the near future. Electrocatalytic water decomposition to produce hydrogen and oxygen, which is a pollution-free method, is likely to become a key project to solve energy shortages. In this study, NiCo-MOF precursor was synthesized through a one-step hydrothermal process, followed by phosphating treatment in a tube furnace to generate Cu-NiCoP catalyst with aggregated nanoblocks, as well as Zn-NiCoP catalyst with aggregated nanosheets and nanoneedles. The prepared catalysts exhibit high activity in hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and overall water decomposition in the electrolysis cell. The overpotential of Cu-NiCoP sample is only 250 mV at 10 mA cm−2 for OER, while the overpotential of Zn-NiCoP is only 150 mV at 10 mA cm−2 for HER. The composed electrolysis cell can achieve a current density of 10 mA cm−2 with only 1.68 V, and has superior durability. It is worth noting that the catalysts were also tested in seawater environment. By comparing the performance in KOH and seawater environments, it was found that the performance of the catalysts would decrease in seawater environment. During the stability test, it was found that the impurities in seawater would corrode the catalyst itself, and the performance would stabilize after a period of reaction. Density functional theory (DFT) demonstrates that the Zn-NiCoP electrode presents optimal hydrogen Gibbs frees energy, thus speeding up the reaction kinetics. In summary, our work demonstrates that the doping of transition metal phosphides with metal elements has great potential and proposes novel views and directions for electrochemical seawater splitting.

Construct Ni–SnO2 core coated amorphous Ni(BO2)2 shell boosts water splitting for hydrogen production

Through a simple redox reaction, the precursor of Ni (OH)2 mixed with SnO2 was in situ transformed into a core-shell structure with elemental Ni blend SnO2 as the core and nickel metaborate as the shell. The metaborate shell is an excellent adsorption site for water molecules, which paves the way for subsequent hydride adsorption. When a small amount of SnO2 is mixed with elemental Ni, the electronic structure is optimized, and the electron enrichment of Ni is realized, making the hydrogen adsorption performance better. This core-shell synergy promotes the Vomer step in HER, thereby enhancing HER performance. In addition, Ni–Sn@NiBO/NF possesses larger electrochemical surface area and smaller charge transfer resistance. Only an overpotential of 22 mV is needed to drive a current density of 10 mA cm−2, indicating the excellent HER performance of the Ni–Sn@NiBO/NF catalyst. At high current density of 50 mA cm−2, the overpotential is only 79 mV. When Ni–Sn@NiBO/NF is used as the bifunctional catalyst for coupling HER and OER, the voltage is only 1.595 V at 10 mA cm−2. It shows that the catalyst has great application potential in electrocatalytic water decomposition to produce hydrogen.

Electrochemical Production of Hydrogen from Hydrogen Sulfide Using Cobalt Cadmium Sulfide.

The electrocatalytic decomposition of H2S is a promising technology for H2 production as well as for targeting environmental pollution. But due to the lack of low-cost and efficient electrocatalysts, this technology for H2 production is not being explored much. Moreover, the highly toxic and copious waste H2S released from industries is rarely encountered in the scientific domain. Herein, we have designed a highly efficient electrocatalyst, i.e., CoCd(x:y)Sn, as an anode catalyst for sulfide oxidation reaction (SOR). This optimized catalyst could drive the anode reaction at an onset potential of 0.25 V vs reversible hydrogen electrode (RHE), which was 1.27 V lower than that required for the water oxidation reaction. Moreover, we have achieved 98% H2 Faradaic efficiency with remarkable stability of 120 h. Thus, this method paves a path to high-value utilization of hazardous waste H2S and demonstrates its great potential for hydrogen production and sulfur toward sustainable energy applications.

Recent Advances in Manganese-Based Materials for Electrolytic Water Splitting.

Developing earth-abundant and highly effective electrocatalysts for electrocatalytic water splitting is a prerequisite for the upcoming hydrogen energy society. Recently, manganese-based materials have been one of the most promising candidates to replace noble metal catalysts due to their natural abundance, low cost, adjustable electronic properties, and excellent chemical stability. Although some achievements have been made in the past decades, their performance is still far lower than that of Pt. Therefore, further research is needed to improve the performance of manganese-based catalytic materials. In this review, we summarize the research progress on the application of manganese-based materials as catalysts for electrolytic water splitting. We first introduce the mechanism of electrocatalytic water decomposition using a manganese-based electrocatalyst. We then thoroughly discuss the optimization strategy used to enhance the catalytic activity of manganese-based electrocatalysts, including doping and defect engineering, interface engineering, and phase engineering. Finally, we present several future design opportunities for highly efficient manganese-based electrocatalysts.

Lattice stain dominated hydrazine oxidation reaction in single-metal-element nanosheet

Electrocatalytic water decomposition is an essential pathway for large-scale preparation of high-purity hydrogen, while the conventional oxygen evolution reaction (OER) with a kinetically sluggish four-electron process becomes a huge challenge for its further application. Hydrazine oxidation reaction (HzOR) is considered an effective strategy to replace the sluggish OER process, attributed to its lower thermodynamic oxidation potential. Here, porous rhodium nanosheets (Rh-NSs) with tunable lattice strain are successfully obtained by directly annealing metastable trigonal rhodium oxide (Tri-RhO2) in a hydrogen atmosphere. More importantly, ligand and synergetic effects can be effectively avoided in a single-metal-element system, providing an ideal model electrocatalyst for understanding the correlation between reactivity and lattice strain. The electrochemical results show that the optimal Rh-NSs-300 (the Tri-RhO2 precursor is annealed at 300 °C) may deliver ultralow working potential (vs. RHE) of −103 mV at the current density of 10 mA cm−2 with a Tafel slope of 15.4 mV dec-1 for HzOR. In addition, the working potential (vs. RHE) of Rh-NSs-300 only drops 35 mV after the 72 h test by chronopotentiometry method at the constant current density of 10 mA cm−2. Density functional theory (DFT) calculations indicate that HzOR can more easily occur on Rh-NSs with tunable compressive strain than pure Rh.

Biohybrid Molecule-Based Photocatalysts for Water Splitting Hydrogen Evolution.

The problems of resource depletion and environmental pollution caused by the excessive use of fossil fuels greatly restrict the rapid development of human technology and industry, which has led to a high demand for the development of new and clean energy sources. Hydrogen, due to its high calorific value and environmentally friendly combustion products, is undoubtedly a very promising energy carrier. The current methods of industrial hydrogen production are mainly water electrocatalytic decomposition or fossil fuels conversion, which also results in the waste of other energy sources. Since only one-step is involved during the conversion from solar to chemical energy and thus unnecessary energy waste is avoided, solar energy photocatalytic decomposition of water provides a more viable method for hydrogen production. The utilization of biohybrid molecules, which are widely available in nature and environmentally friendly, further reduce the cost of such photocatalytic systems. This Review discusses the research progress on hydrogen production using biohybrid molecules for photocatalytic hydrogen evolution. The basic reaction mechanism, general types and system structures about biohybrid molecule-based photocatalysts are summarized. The current challenges and prospects in the research of water splitting hydrogen evolution by biohybrid molecules photocatalysts are presented.

Carbon-quantum-dots-involved Fe/Co/Ni phosphide open nanotubes for high effective seawater electrocatalytic decomposition

The hollow materials with open structure can accelerate the mass transfer and bubble release rate, which have attracted tremendous attention for electrocatalytic water splitting. In this work, a unique tri-metal phosphide open nanotube structure [FeCoNiP@carbon quantum dots, FCNP@CQDs] is firstly fabricated by a selected etching and phosphating process with a MIL-88A@CQDs (MIL stands for Material of Institute Lavoisier) as the precursor. Benefiting from their open structure, FCNP@CQDs exhibit excellent catalytic performance. In alkaline seawater solution, a low overpotential of 268 mV is required to reach 20 mA cm−2 current density for oxygen evolution reaction, while the η20 of hydrogen evolution reaction is 150 mV. The FCNP@CQDs//FCNP@CQDs electrolyzer requires a voltage of 1.61 V to reach 10 mA cm−2. The integrated strategy of CQDs-doping and construction of hollow open structures may open a new and relatively unexplored path for fabricating high-performance seawater splitting catalysis.

A Facile MOF Based Iron-Molybdenum Bimetallic Electrode Material Preparation for Hydrogen Evolution

Hydrogen energy has become the most potential energy source due to its high calorific value and environment-friendly combustion products. However, there are huge economic problems in hydrogen storage and transportation. Hydrogen can be prepared by catalysis in a way of reducing cost and speeding up speed which is the core idea of electrocatalytic water decomposition for hydrogen production. In this work, we developed an electrode material for Hydrogen evolution reaction (HER) bimetallic catalyst, and achieved that the hydrogen overpotential produced by acidic non-precious metal catalyst under acidic environment was only 275mV. More importantly, a good idea was provided for bimetallic co-catalysis of HER.

Research progress on MOFs and their derivatives as promising and efficient electrode materials for electrocatalytic hydrogen production from water.

Hydrogen energy is considered to be the most potential "ultimate energy source" due to its high combustion calorific value, cleanliness, and pollution-free characteristics. Furthermore, the production of hydrogen via the electrolysis of water has the advantages of simplicity, high efficiency, environmentally safe, and high-purity hydrogen. However, it is also associated with issues such as high-power consumption for the reaction and limited large-scale application of noble metal catalysts. Metal-organic frameworks (MOFs) are porous composite materials composed of metal ions and organic functional groups through orderly coordination with large specific surface areas and large porosity. Herein, we focus on the research status of MOFs and their transition metal derivatives for electrocatalytic water splitting to produce hydrogen and briefly describe the reaction mechanism and evaluation parameters of the electrocatalytic hydrogen evolution and oxygen evolution reactions. Furthermore, the relationship between the catalytic behavior and catalytic activity of different MOF-based catalysts and their morphology, elemental composition, and synthetic strategy is analyzed and discussed. The reasons for the excellent activity and poor stability of the original MOF materials for the electrolysis of water reaction are shown through analysis, and using various means to improve the catalytic activity by changing the electronic structure, active sites, and charge transfer rate, MOF-based catalysts were obtained. Finally, we present perspectives on the future development of MOFs for the electrocatalytic decomposition of water.