Efficient Trifunctional Electrocatalysts Research Articles

Constructing Dual-Phase Co9S8-CoMo2S4 Heterostructure as an Efficient Trifunctional Electrocatalyst for Oxygen Reduction, Oxygen Evolution and Hydrogen Evolution Reactions.

Designing robust, efficient and inexpensive trifunctional electrocatalysts for the oxygen reduction reaction (ORR), oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is significant for rechargeable zinc-air batteries and water-splitting devices. To this end, constructing heterogenous structures based on transition metals stands out as an effective strategy. Herein, a dual-phase Co9S8-CoMo2S4 heterostructure grown on porous N, S-codoped carbon substrate (Co9S8-CoMo2S4/NSC) via a one-pot synthesis is investigated as the trifunctional ORR/OER/HER electrocatalyst. The optimized Co9S8-CoMo2S4/NSC2 exhibits that ORR has a half-wave potential of 0.86 V (vs. RHE) and the overpotentials at 10 mA cm-2 for OER and HER are 280 and 89 mV, respectively, superior to most transition-metal based trifunctional electrocatalysts reported to date. The Co9S8-CoMo2S4/NSC2-based zinc-air battery (ZAB) has a high open-circuit voltage (1.41 V), large capacity (804 mAh g-1) and highly stable cyclability (97 h at 10 mA cm-2). In addition, the prepared Co9S8-CoMo2S4/NSC2-based ZAB in series can self-drive the corresponding water-splitting device. The dual-phase Co9S8-CoMo2S4 heterostructure provides not only multi-type active sites to drive the ORR, OER and HER, but also high-speed charge transfer channels between two phases to improve the synergistic effect and reaction kinetics.

Cobalt Molybdenum Telluride as an Efficient Trifunctional Electrocatalyst for Seawater Splitting

A mixed-metal ternary chalcogenide, cobalt molybdenum telluride (CMT), has been identified as an efficient tri-functional electrocatalyst for seawater splitting, leading to enhanced oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and oxygen reduction reaction (ORR). The CMT was synthesized by a single step hydrothermal technique. Detailed electrochemical studies of the CMT-modified electrodes showed that CMT has a promising performance for OER in the simulated seawater solutions, exhibiting a small overpotential of 385 mV at 20 mA cm−2, and superior catalyst durability for prolonged period of continuous oxygen evolution. Interestingly, while gas chromatography analysis confirmed the evolution of oxygen in an anodic chamber, it showed that there was no chlorine evolution from these electrodes in alkaline seawater, highlighting the novelty of this catalyst. CMT also displayed remarkable ORR activity in simulated seawater as indicated by its four-electron reduction pathway forming water as the dominant product. One of the primary challenges of seawater splitting is chlorine evolution from the oxidation of dissolved chloride salts. The CMT catalyst successfully and significantly lowers the water oxidation potential, thereby separating the chloride and water oxidation potentials by a larger margin. These results suggest that CMT can function as a highly active tri-functional electrocatalyst with significant stability, making it suitable for clean energy generation and environmental applications using seawater.

Transition metal embedded MoS2 as efficient trifunctional electrocatalyst: A computational study

In the advancement of electrochemical energy systems, multifunctional catalysts for the oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), and oxygen evolution reaction (OER) are indispensable. Moreover, catalysts produced by incorporating transition metals into two-dimensional materials via substitutional modification have demonstrated remarkable efficacy. The present study examines the prospective uses of transition metal (TM= Nb, Co, In, and Re) dopants comprising 10% Niobium, Rhenium, Cobalt, and Indium in 2D MoS2. The density functional theory has been utilized to study the atomic level interaction. Based on the result, it can be observed that Nb-doped MoS2 has a ΔGH value of 0.06 eV, which signifies its remarkable HER capability when compared to pristine MoS2 and other doped versions. Our analysis for OER and ORR activities reveals that Co doped MoS2 exhibit superior performance compared to both the pristine and other doped versions of TM-MoS2, with an overpotential value ɳOER = 1.00 V and ɳORR = 0.77 V. A modification in electronic properties is examined by analysing the partial density of states during the HER and OER processes. The number of potential candidates suggested by the present findings will aid in the development of TM-doped MoS2-based electrocatalysts.

A self‐powered system to electrochemically generate ammonia driven by palladium single atom electrocatalyst

AbstractThe utilization of single atoms (SAs) as trifunctional electrocatalyst for nitrogen reduction, oxygen reduction, and oxygen evolution reactions (NRR, ORR, and OER) is still a formidable challenge. Herein, we devise one‐pot synthesized palladium SAs stabilized on nitrogen‐doped carbon palladium SA electrocatalyst (Pd‐SA/NC) as efficient trifunctional electrocatalyst for NRR, ORR, and OER. Pd‐SA/NC performs a robust catalytic activity toward NRR with faradaic efficiency of 22.5% at −0.25 V versus reversible hydrogen electrode (RHE), and the relative Pd utilization efficiency is enhanced by 17‐fold than Pd‐NP/NC. In addition, the half‐wave potential reaches 0.876 V versus RHE, amounting to a 58‐time higher mass activity than commercial Pt/C. Moreover, the overpotential at 10 mA cm−2 is as low as 287 mV for Pd‐SA/NC, outperforming the commercial IrO2 by 360 times in turnover frequency at 1.6 V versus RHE. Accordingly, the assembled rechargeable zinc‐air battery (ZAB) achieves a maximum power density of 170 mW cm−2, boosted by 2.3 times than Pt/C–IrO2. Two constructed ZABs efficiently power the NRR‐OER system to electrochemically generate ammonia implying its superior trifunctionality.

RuSe2 and CoSe2 Nanoparticles Incorporated Nitrogen-Doped Carbon as Efficient Trifunctional Electrocatalyst for Zinc-Air Batteries and Water Splitting.

The development of affordable, highly active, and stable trifunctional electrocatalysts is imperative for sustainable energy applications such as overall water splitting and rechargeable Zn-air battery. Herein, we report a composite electrocatalyst with RuSe2 and CoSe2 hybrid nanoparticles embedded in nitrogen-doped carbon (RuSe2CoSe2/NC) synthesized through a carbonization-adsorption-selenylation strategy. This electrocatalyst is a trifunctional electrocatalyst with excellent hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) activities. An in-depth study of the effect of Se on the electrocatalytic process was conducted. Notably, the incorporation of Se moderately adjusted electronic structure of Ru and Co, enhancing all three types of catalytic performance (HER, η10 = 31 mV; OER, η10 = 248 mV; ORR, E1/2 = 0.834 V) under alkaline condition with accelerated kinetics and improved stability. Density functional theory (DFT) calculation reveals that the (210) crystal facet of RuSe2 is the dominant HER active site as it exhibited the lowest ΔGH* value. The in situ Raman spectra unravel the evolution process of the local electronic environment of Co-Se and Ru-Se bonds, which synergistically promotes the formation of CoOOH as the active intermediate during the OER. The superior catalytic efficiency and remarkable durability of RuSe2CoSe2/NC as an electrode for water splitting and zinc-air battery devices demonstrate its great potential for energy storage and conversion devices.

Synergistic interactions of electronic modulation and low crystallization in Ru-RuO2/C heterostructure for highly efficient multifunctional electrocatalysis

Developing electrocatalysts with multifunctional performance is crucial for hydrogen energy storage and conversion, but still a great challenge. Herein, an efficient trifunctional electrocatalyst with heterostructure is fabricated by a sequential reduction and annealing approach. With different annealing atmospheres, Ru-RuO2/C electrocatalysts having different Ru/RuO2 atomic ratios or different crystallinities were achieved. Among these electrocatalysts, Ru-RuO2/C annealed from N2-air mixed atmosphere (Ru-RuO2/C 250NA) displays the most excellent performance, affording overpotential values of 30.63 mV for alkaline hydrogen evolution reaction (HER) and 273.42 mV for alkaline oxygen evolution reaction (OER) at 10 mA cm−2, much lower than those of state-of-the-art Pt/C (η10, HER = 46.57 mV) and RuO2 (η10, OER = 288.99 mV). Not only that, it also delivers favorable activity for alkaline hydrogen oxidation reaction (HOR), with 2.1 times of mass specific exchange current density than that of Pt/C. The experimental and theoretical investigations prove the electron rearrangement at Ru and RuO2 interface with abundant defects and amorphous/crystalline structures. The synergistic effect of dual active sites simultaneously optimizes H and OH as well as H2O adsorption energies, endowing the Ru-RuO2/C 250NA as the preferential electrocatalysts.

Regulation of hydrogen binding energy via oxygen vacancy enables an efficient trifunctional Rh-Rh2O3 electrocatalyst for fuel cells and water splitting

Developing multi-functional electrocatalysts is of great practical significance for fuel cells and water splitting. Herein, Rh-Rh2O3 nanoclusters are prepared and the surface oxygen vacancy content is regulated elaborately by post-treatment. The optimized Rh-Rh2O3/C-400 exhibits superior trifunctional catalytic activity for hydrogen oxidation reaction (HOR), hydrogen evolution reaction (HER) and hydrazine oxidation reaction (HzOR), i.e., the mass activity for HOR is 2.29 mA μgRh-1, and the overpotential for HER and HzOR at 10 mA cm−2 is as low as 12 mV and 31 mV, respectively, superior to the benchmark Pt/C. Rh-Rh2O3/C-400 also displays promising performance in practical devices, with the H2-O2 anion-exchange-membrane fuel cell delivering a peak power density of 0.66 W cm−2, and the hydrazine-assisted water splitting electrolyzer requiring a low electrolysis voltage of 0.161 V at 0.1 A cm−2. The experimental and theoretical investigations discover that the hydrogen binding energy (HBE) is linearly depended on surface oxygen vacancy contents, and the HBE directly determines the catalytic activity for HOR, HER and HzOR. This work not only innovates an efficient Rh-based nanocluster tri-functional electrocatalyst, but also eludicates the intrinsic relationship of surface structure-intermediate adsorption-catalytic activity.

Surface regulation of perovskite oxides with cation preference for efficient trifunctional electrocatalysts

This study presents a straightforward chemical approach to induce cationic surface defects on SrCoO3-δ (SCO) perovskites by selectively etching a-site Sr elements on the surface. The modified SCO-30 catalyst from this method exhibits an optimized thickness of cobalt-rich amorphous layer enriched with oxygen vacancies. This modification enhances the trifunctional catalytic activity for oxygen evolution reaction (OER), oxygen reduction reaction (ORR), and hydrogen evolution reaction (HER) in an alkaline electrolyte. Importantly, the perovskite's structure remains unchanged during the surface engineering process. These findings underscore cationic defect engineering as an effective strategy for the rational design of high-performance electrocatalysts, showcasing potential applications in diverse electrochemical processes.

A novel thiophene-linked metalloporphyrin conjugated polymer: a highly efficient trifunctional electrocatalyst for overall water splitting and oxygen reduction

A thiophene-linked porphyrin (TP) conjugated polymer that serves as a support for anchoring single transition metal atoms (TM–N4/TP) exhibits trifunctional merit for the HER/OER/ORR.

Heterointerface engineering of assembled CoP2 on N-modified carbon as efficient trifunctional electrocatalysts for Zn-Air batteries and overall water splitting

Heterointerface engineering of assembled CoP2 on N-modified carbon as efficient trifunctional electrocatalysts for Zn-Air batteries and overall water splitting

Transition Metal Functionalized C30N12S6 as High-Performance Trifunctional Catalysts with Integrated Descriptors toward Hydrogen Evolution, Oxygen Evolution, and Oxygen Reduction Reactions: A Case of High-Throughput First-Principles Screening within the Framework of TM-N2@C30N10S6.

In energy conversion and storage technologies, the design of highly efficient trifunctional electrocatalysts integrating with the high hydrogen evolution reaction (HER) and oxygen evolution/reduction reaction (OER/ORR) activities is highly desirable. Herein, utilizing first-principles computations, a novel periodically ordered macropore C30N12S6 monolayer was proposed, and the stability analysis attests to its good stability. Single transition metal (TM) atom anchored onto this newly proposed C30N12S6 monolayer to form single-atom catalysts, as achieved by TM-N2@C30N10S6, among which the Co-N2@C30N10S6 is the most promising multifunctional catalyst toward HER/OER/ORR with low overpotential of 0.01/0.59/0.3 V; meanwhile, the Rh-N2@C30N10S6 can be used as a bifunctional OER/ORR catalyst with low overpotential of 0.37/0.44 V, overmatching the landmark Pt (111) and IrO2/RuO2 catalysts. Particularly, the TM-d orbital in TM@CNS is remarkably hybridized with the O-p orbital of oxygenated intermediates, so that the lone electrons initially located at the antibonding orbital pair up and fill the downward bonding orbital, allowing OH* to be suitably adsorbed on TM@CNS, enhancing the catalytic performance. The relevant attributes, such as good stabilities and metallic features, ensured their applications in ambient conditions. Moreover, multilevel descriptors were constructed to clarify the origin of activity on TM@CNS, such as ΔGOH* (Gibbs free energy of OH*), εd (d-band center), COHP (crystal orbital Hamilton population), Nd/Nd+s (number of d/d + s electrons) and φ (descriptor), among which the filling of outer d-electrons of TM atom significantly affects the value of ΔGOH* that can determine the overpotential and, thus, become a key descriptor.

Pyrolysis-free cobalt porphyrin coordination polymer as electrocatalyst for Zn-air batteries and water splitting

The development of high-performance and stable trifunctional electrocatalysts for oxygen reduction reaction (ORR), oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) plays key role in the practical application of renewable energy systems. Herein, we report a pyrolysis-free synthesis of a CoNC based porphyrin cobalt coordination polymer electrocatalyst by using 5,10,15, 20-tetrad-[4′-(terpyridinyl) phenyl] porphyrin and cobalt bivalent ions. The polymer exhibits pronounced trifunctionality at a low ORR onset potential of 0.87 V vs. RHE, and an overpotentials of 378 and 210 mV at 10 mA cm−2 for the OER and HER with substantial stability in alkaline media. In the constructed aqueous Zn-air battery, it displays satisfied specific capacity of 723 mAh g−1 and appreciable stability for 85 h. Density functional theory computations reveal that TTBPP-Co exhibits excellent donor–acceptor characteristics with HOMO-LUMO band gap of 1.87 eV. This work provides a new design of metal porphyrin coordination polymers as efficient trifunctional electrocatalysts for clean energy applications.

Hierarchical NiCo-LDH@MoS2/CuS composite as efficient trifunctional electrocatalyst for overall water splitting and asymmetric supercapacitor

The development of highly active and long-lived multifunctional electrocatalysts is a key priority to boost clean renewable energy technologies. It is difficult to construct such hierarchically structured materials with an efficient synergistic heterostructure technique to improve electrochemical performance. Here, a novel hierarchical NiCo-LDH@MoS2/CuS heterostructure (HS) was prepared by facile two-step hydrothermal synthesis for water splitting and supercapacitor applications. The hierarchical network of NiCo-LDH is grown on MoS2/CuS and is put forward based on various physio-chemical analysis. The hierarchical structure and heterostructure synergistic effect result in excellent HER (114 mV@10 mA cm−2) and OER (310 mV@10 mA cm−2) activity. Two electrode water-splitting cells (NiCo-LDH@MoS2/CuS||NiCo-LDH@MoS2/CuS) achieved a cell potential of 1.57 V@10 mA cm−2. NiCo-LDH@MoS2/CuS also exhibits the electrochemical charge storage property of 147.16 mAh g−1@0.2 A g−1. NiCo@MoS2/CuS||AC flexible solid-state asymmetric supercapacitor (FSSC) demonstrated charge storage of 226.08 mAh g−1 and energy density of 152.60 W h kg−1@0.2 A g−1 with 90.05 % retention rate, demonstrated the excellent cyclic and structural stability. The acquired knowledge from this study could be a novel strategy for designing hierarchical LDH-based heterostructures as electrode materials for water splitting and energy storage devices.

Self-catalyzed Co, N-doped carbon nanotubes-grafted hollow carbon polyhedrons as efficient trifunctional electrocatalysts for zinc-air batteries and self-powered overall water splitting

It is still essential and challenging to explore inexpensive and versatile electrocatalysts for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER), for the development of rechargeable zinc-air batteries (ZABs) and overall water splitting. Herein, a rambutan-like trifunctional electrocatalyst is fabricated by re-growth of secondary zeolitic imidazole frameworks (ZIFs) on ZIF-8-derived ZnO and the following carbonization treatment. Co nanoparticles (NPs) are encapsulated into N-doped carbon nanotubes (NCNT) grafted N-enriched hollow carbon (NHC) polyhedrons to form the Co-NCNT@NHC catalyst. The strong synergy between the N-doped carbon matrix and Co NPs endows Co-NCNT@NHC with trifunctional catalytic activity. The Co-NCNT@NHC displays a half-wave potential of 0.88 V versus RHE for ORR in alkaline electrolyte, an overpotential of 300 mV at 20 mA cm−2 for OER, and an overpotential of 180 mV at 10 mA cm−2 for HER. Impressively, a water electrolyzer is successfully powered by two rechargeable ZABs in series, with Co-NCNT@NHC as the 'all-in-one' electrocatalyst. These findings are inspiring for the rational fabrication of high-performance and multifunctional electrocatalysts intended for the practical application of integrated energy-related systems.

Bamboo-like N-doped carbon tubes encapsulated Co2P–Fe2P derived from zeolitic imidazolate framework as an efficient trifunctional electrocatalyst for water splitting and Zn-air batteries

The development of high-performance and stable trifunctional electrocatalysts is a pressing challenge for the practical application of water splitting and regenerative Zn-air batteries. Herein, bamboo-like N-doped carbon tubes encapsulated Co2P–Fe2P nanoparticles (CoFe-PN/C) was fabricated via a facile template-sacrificial approach by using CoZn-ZIF trapping Fe3+ (CoFeZn/C) as the precursor. The incorporation of Fe3+ was achieved by the one-pot synthesis approach during crystallization of ZIF, which led to the generation of the unique bamboo-like tube structure under the condition of simultaneous phosphating and carbonization. Benefiting from the large surface area, the optimized electronic structure of active sites and the unique bamboo-like nanotube, the resultant CoFe-PN/C can be used as the trifunctional electrocatalyst possessing a small overpotential at 10 mA cm−2 for the HER (178 mV) and OER (300 mV), as well as a high half-wave potential of 0.884 V for ORR (40 mV more positive than that of commercial 20 wt% Pt/C). Moreover, the self-designed CoFe-PN/C||CoFe-PN/C alkaline electrolyzer driving 50 mA cm−2 only need operating potential of 1.84 V and the maximum discharge power density of the CoFe-PN/C-assembled ZABs could achieve 152.0 mW cm−2, superior to those of Pt/RuO2 couple. This work will facilitate the development and application of trifunctional electrocatalysts based on bi-transition metallic phosphides for energy conversion and storage technology.

BN/Cu/CNT nanoparticles as an efficient tri-functional electrocatalyst for ORR and OER

Preparing economic, stable, and highly efficient non-precious-metal materials for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is of great significance to the development of storage technologies and energy conversion. In this manuscript, we report a novel Cu based nano-catalyst as an electrode material fabricated by complexation-reduction method. Benefit from the stable of h-NB and the good electrical conductivity of CNT, the tri-functional electrocatalyst BN/Cu/CNT displays enhanced activity towards ORR and with the high current density of 0.95 mA/cm2, which is comparable to that of commercial Pt/C catalyst (cathodic peak current: 1.05 mA/cm2). The BN/Cu/CNT also demonstrates high catalyst activity for the OER. From the rotating disk electrode and rotating ring-disk electrode tests, the number of electrons exchanged during the ORR is revealed to be 3.92, suggesting a 4e− pathway of O2 reduction to H2O. The as prepared catalyst also has good stability and superior methanol tolerance to the commercial Pt/C catalyst in alkaline medium. Thus, it is anticipated that the BN/Cu/CNT catalyst is surely helpful for providing a new space to develop Pt-free catalyst.

Surface-enriched ultrafine Pt nanoparticles coupled with defective CoP as efficient trifunctional electrocatalyst for overall water splitting and flexible Zn-air battery

Developing multifunctional electrocatalysts toward energy-related reactions could reduce the cost and improve the utilization efficiency of raw materials. Herein, defective CoP decorated with ultrafine Pt nanoparticles (Pt/d-CoP/NPC) with multifunctional electrocatalytic performances is prepared via facile pyrolysis and following chemical reduction process. The as-synthesized Pt/d-CoP/NPC owns high half-wave potential of 0.82 V for oxygen reduction reaction with excellent stability in 0.1 mol/L KOH. Density functional theory calculations demonstrate that the adsorption energy of *OO at Pt/d-CoP/NPC is stronger compared to Pt, yielding higher catalytic activity for ORR. Moreover, the resultant electrocatalyst possesses excellent catalytic activities with low overpotentials toward hydrogen evolution reaction (33 mV in 1 mol/L KOH, 6 mV in 0.5 mol/L H2SO4 and 70 mV in 1 mol/L PBS) and oxygen evolution reaction (320 mV) at 10 mA/cm2. Water-splitting and rechargeable Zn-air batteries assembled with the as-synthesized Pt/d-CoP/NPC as electrodes exhibit outstanding activity and long-range stability. Remarkably, sustainable energies and homemade Zn-air battery can efficiently drive the Pt/d-CoP/NPC electrolyzer with sumless hydrogen bubbles generated, verifying the potential applications for renewable energy storage.

Single Cu atoms confined in N-doped porous carbon networks by flash nanocomplexation as efficient trifunctional electrocatalysts for Zn-air batteries and water splitting

Constructing efficient trifunctional single-atom electrocatalysts is exceedingly alluring and challenging for enhancing the efficiency of water splitting and Zn-air batteries (ZABs). Herein, a novel N-doped porous carbon network (SC-CuSA-NC) catalyst with Cu single atoms is constructed via flash nanocomplexation (FNC) technology and a double-network gel-limiting strategy. The novelty of this method lies in the combination of physical confinement and chemical confinement by FNC, which enables uniform spatial isolation and atomic-level dispersion of Cu atoms in the hydrogel, effectively inhibits the migration of Cu during synthesis, and achieves accurate and controllable preparation of Cu single atoms catalyst. Benefiting from the highly active Cu–N4 sites and distinct interconnected three-dimensional porous carbon network, SC-CuSA-NC shows superior ORR/OER/HER performance. Significantly, the ZAB assembled by SC-CuSA-NC displays a high specific capacity (775.0 mAh g−1) and could effectively drive water splitting (1.58 V at 10 mA cm−2). This work expands the synthesis method of single-atom catalysts and provides a new approach for the accurate and controllable synthesis of electrocatalysts for water splitting and ZABs.

Dicyandiamide-assisted synthesis of N-doped porous CoMn-Nx@N-C carbon nanotube composites via MOFs as efficient trifunctional electrocatalysts in the same electrolyte.

The development of low-cost, long-term stability, and good oxygen reversible catalytic reaction (ORR/OER) and hydrogen evolution (HER) activity under the same electrolyte concentration of electrocatalytic materials has an important role in the construction of large-scale applications and more valuable sustainable energy systems. Among them, the representative CoMn-Nx@N-C-900-0.2 showed good ORR/OER/HER catalytic activity in 0.1 M KOH alkaline electrolyte, specifically manifested by its half-wave potential E = 0.84 V in the ORR test, which was better than that of commercial Pt/C. The total oxygen electrode activity index of OER/ORR was E = 0.79 V, and it also showed good HER performance. When the current density was 10 mA cm-2, the operating potential was E = -0.266 V. The synergistic effects of the CoMn bimetallic alloy, tubular layered porous structure, which exposed more active area and various nitrogen species such as CoMn-Nx, were the main reasons for the improvement of the trifunctional catalytic performance of electrocatalytic materials. The synthesis strategy and analysis of the electrocatalyst performance provide a new reference for the development of multifunctional materials with high catalytic performance.

Cobalt(ii)-bridged triphenylamine and terpyridine-based donor–acceptor coordination polymer as an efficient trifunctional electrocatalyst

A new coordination polymer for trifunctional electrocatalysis (ORR, OER, and HER) synthesized via Schiff base condensation and in situ self-assembly using triphenylamine and Co(ii)-terpyridine ligand.