Electrocatalytic Activity For HER Research Articles

Construction of carbon hybridized Co3S4/NiS microspheres on nickel foam for enhanced electrocatalytic hydrogen evolution in all-pH water and seawater

Interface engineering can expose sufficient active sites and facilitate the hydrogen evolution reaction kinetics. Herein, we developed a strategy with the designed deep eutectic solvents dissolved CoO as precursors to prepare Co3S4 and NiS nanodots and carbon hybridized microspheres on the surface of nickel foam (Co3S4/NiS/C/NF) via a one-step sulfidation-pyrolysis method. The composite catalysts have abundant tightly coupled heterogeneous interfaces between Co3S4 and NiS nanodots, the hybridized carbon layers and NF, which not only improve the electron transfer efficiency but also increase the number of active sites. The optimized Co3S4/NiS/C/NF electrodes exhibit excellent electrocatalytic HER activity in all-pH water and natural seawater, and were even superior to the Pt/C electrode at high current densities. In 0.5 M H2SO4, 1.0 M KOH, 1.0 M PBS, and natural seawater electrolytes, current densities as high as 10 mA cm−2 were obtained at remarkably low overpotentials of only 49, 72, 93, and 261 mV respectively. This work provides new insights for the development of excellent electrocatalysts in all-pH water and natural seawater applications.

The excellent electrocatalytic HER activity and photogalvanic effect of WS2/Ga2O3 based on Density Functional Theory

This study is based on density functional theory, studied structure and electronic properties, optical properties, electrocatalytic water splitting to produce H2, and electrical properties of the WS2/Ga2O3 heterojunction. By analyzing the photoelectric characteristics, we find that the WS2/Ga2O3 heterojunction has built-in electric field, which can separate photogenerated carriers and effectively capture visible light for visible light photocatalysis. In addition, the change of Gibb free energy (ΔG) tends to 0, so when the WS2/Ga2O3 heterojunction is used as a catalyst, the hydrogen evolution reaction tends to proceed spontaneously. Interestingly, by analyzing the electrical properties, we find that the large and obviously changed photogalvanic effect photocurrent is produced with the change of polarization angle and photon energy of the WS2/Ga2O3 heterojunction, and it has the potential to become high-sensitivity optoelectronic detector.

An efficient multifunctional SnS2/g-C3N4 hierarchical nanoflower catalyst for electrocatalytic and photocatalytic applications

The rising energy demand via renewable sources and existence of organic pollutants in water has attracted the world-wide attention to attain sustainable ecosystems. The development of a multi-functional catalyst with significant economic and environmental implications remains a challenge. Herein, we synthesized SnS2/g-C3N4 hierarchical nanoflower using solvothermal method, verified by XRD and FTIR investigations. The surface morphology was analyzed using FESEM, TEM and HRTEM while optical absorption via UV–Vis spectroscopy. SnS2/g-C3N4 displayed outstanding electrocatalytic activity for HER and OER with smaller tafel slope and higher values of current density. The results are in accordance with Cdl and ECSA values, ensuing more active sites and surface area for a catalytic reaction to take place. As-prepared SnS2/g-C3N4 also exhibited 90 % photocatalytic MB deterioration in 90 min upon solar irradiation, following first order kinetics. Type-II mechanism for charge transfer alongwith reactive specie trapping experiment and cyclic stability is also presented. The findings suggests that SnS2/g-C3N4 emerged as proficient catalyst for electrocatalytic and photocatalytic applications.

Heterogeneous Ni-Boride/Phosphide Anchored Amorphous B-C Layer for Overall Water Electrocatalysis.

The rational design of efficient and economical bifunctional electrocatalysts remained a challenge for overall water electrolysis. In this work, the Ni-boride/ phosphide particles anchored amorphous B-doped carbon layer with hierarchical porous characteristics in Ni foam (Ni3P/Ni3B/B-C/NF) was fabricated for overall water splitting. The Boroncarbide (B4C) power was filled and fixed in the NF interspace through the electroplating and electroless plating, and then annealed in vacuum high temperature. The amorphous B-C layer derived from the B4 C not only speeded up the electron transport, but also cooperate with Ni-boride/phosphide to enhance the electrocatalytic activity for HER and OER synergistically. Furthermore, the hierarchical porous architecture of Ni3P/Ni3B/B-C/NF increased space utilization to load more active materials. The self-supported Ni3P/Ni3B/B-C/NF electrode possessed a low overpotential of 212 and 280 mV to deliver 100 mA cm-2 for HER and OER, respectively, and high stability for 48 h. In particular, the electrolyzer constituted with the Ni3P/Ni3B/B-C/NF bifunctional electrocatalyst only required a voltage of 1.59 V at 50 mA cm-2 for water electrocatalysis under alkaline medium, and demonstrated long-term stability for 48 h. This study provides a new technical path for the development of bifunctional of transition metal borides to promote the application of hydrogen production from water splitting.

The electrocatalytic HER activity of MoS2 decorated with adjustable-size ruthenium nanoparticles

MoS2 is a potential electrocatalytic material for its excellent durability and stability. Here, we investigate the electrocatalytic hydrogen evolution reaction performance of MoS2 nanosheets decorated with size-controlled Ru nanoparticles. The MoS2 compounded with 2.46 nm-Ru exhibits the good electrocatalytic performance with overpotential of 53 mV at 10 mA/cm2 in 0.5 M H2SO4 condition. The enhanced electrocatalytic activity of Ru@MoS2 results from accelerated charge migration between the Ru metal and MoS2 semiconductor, as well as the addition of Ru increases the number of active sites on the surface of MoS2. Furthermore, the first-principles calculations demonstrated the ΔGH* of Ru@MoS2 (−0.05 eV) is lower than P–MoS2 (2.04 eV) and the narrowed bandgap facilitates more efficient electron migration. And the theoretical calculations further reveal that the Ru nanoparticles with suitable size at the interface own the ideal ΔGH* by manipulating the D-band center of the Ru.

The dependence of electrocatalytic HER activity of decorated MoS2 with Cu nanoclusters

Molybdenum disulfide is a potential electrocatalytic material for water splitting with excellent stability and durability. Here, the electrocatalytic hydrogen evolution reaction performance of Molybdenum disulfide nanosheets decorated with copper nanoclusters was investigated. The Cu@MoS2–1:10 exhibited remarkable hydrogen evolution reaction activity, with an overpotential as low as 150 mV under acidic conditions. The First-principles calculations further confirmed the superior electrocatalytic performance of Cu@MoS2, with a minimum hydrogen adsorption free energy of -0.10 eV. The improved electrocatalytic activity of Cu@MoS2 arises from the accelerated charge migration at the interface. And the addition of Cu increases the number of active sites on the surface of MoS2. This work could offer insights into the advancement of additional non-precious metals and transition metal dichalcogenides.

Electrocatalytic hydrogen evolution by cobalt(Ⅲ) triphenyl corrole bearing different number of trifluoromethyl groups

Hydrogen production from electrolyzing water is known as the most promising hydrogen production method. To further understand the effect of steric hindrance and electron-withdrawing groups on catalysts, four cobalt triphenyl corroles bearing different number of ortho-trifluoromethyls (1, 2, 3, 4) had been synthesized and used as hydrogen evolution electrocatalysts. These cobalt corroles showed effective electrocatalytic hydrogen evolution activity in organic medium and neutral aqueous medium, with turnover frequency ranging from 100 s−1 to 220 s−1 using 32 equivalents of trifluoroacetic acid proton source in DMF. The electrocatalytic HER goes via competitive ECEC or EECC pathway depending on the used proton source. The electrocatalytic HER activity varies obviously with the number of the peripheral ortho- groups. This work is helpful for the design of new metal corrole HER electrocatalyst.

Decrypting the hydrogen evolution in alkaline water with novel magnetoactive cobalt(II) complex-driven cobalt oxide electrocatalysts.

Under the gravity of future socio-economic development, the viability of water electrolysis still hinges on the accessibility of stable earth-abundant electrocatalysts and net energy efficiency. This work emphasizes the design and synthesis of two newly developed cobalt(II) complexes, [Co(HL)2(NCS)2] (Comono) and [Co2(L)3(CH3OH)]ClO4 (Codi), with a (N,O)-donor ligand, HL (2-methoxy-6-(((2-methoxyphenyl)imino)methyl)phenol). The study delves into understanding their structural, morphological, magnetic, and charge transport characteristics. Moreover, the study explores the potential of these complexes in catalyzing hydrogen production through heterogeneous electrocatalysis. The X-ray crystal structure of Comono reveals the octahedral geometry of the Co(II) ion, adopting two HL units and two NCS- units. The Codi complex exhibits a doubly-phenoxo-O-bridged (μ1,1) dinuclear complex, forming a typical octahedral geometry for both the Co(II) centres in coupling with three units of L-. Temperature-dependent magnetic susceptibility measurements showed that all of the Co(II) ion in Comono shows a typical paramagnetic behaviour for high spin octahedral Co(II) ions while the Co(II) centres in Codi are coupled with doubly-phenoxo-bridges bearing weak ferromagnetic characteristics at low temperature. Electron transport properties of the Co(II) complex-mediated Schottky device address the superior carrier mobility (μ) for Codi (9.21 × 10-5) over Comono (2.02 × 10-5 m2 v-1 s-1) with respective transit times of 1.70 × 10-9 and 7.77 × 10-9 s. Additionally, electron impedance spectral analysis supports the lower electrical transport resistance of Codi relative to Comono. The heterogeneous electrocatalytic HER activity of Codi and Comono in 0.1 M KOH shows excellent electrocatalytic efficiency in terms of the various electrochemical parameters. Constant potential electrolysis, multi-cycle CVs, and post-HER analysis reveal the pre-catalytic nature of the complexes, which in turn delivers Co3O4 nanoparticles as the active catalysts for efficient hydrogen evolution.

A cobalt porphyrin-bridged covalent triazine polymer-derived electrode for efficient hydrogen production.

Pronounced compositional regulation and microstructure evolution have a significant influence on hydrogen electrocatalysis. Herein, for the first time, we demonstrate that N,Co-codoped carbon supported Co5.47N nanoparticles (Co5.47N/N,Co-C-800) derived from a nitrogen-rich porphyrin-bridged covalent triazine polymer (CoTAPPCC) are an effective electrocatalyst for the HER in 1.0 M KOH when compared to CoCo2O4/N,Co-C-900 (pyrolysis at 900 °C) and CoO/N,Co-C-1000 (pyrolysis at 1000 °C). The structural and morphological variations of CoTAPPCC at different heat treatment temperatures were investigated through various spectroscopic techniques. We reveal that electrocatalytic HER activity is temperature- and component-dependent. The overpotentials for Co5.47N/N,Co-C-800 to reach current densities of 10 and 100 mA cm-2 were determined to be 76 and 229 mV, respectively, outperforming many other state-of-the-art HER electrocatalysts. This work also sheds light on the influence of calcination temperature on the electrocatalytic HER of final samples.

Axial ligand-induced high electrocatalytic hydrogen evolution activity of molecular cobaloximes in homo- and heterogeneous medium.

Three new molecular cobaloxime complexes with the general formula [ClCo(dpgH)2L] (1-3), where L1 = N-(4-pyridylmethyl)-1,8-naphthalimide, L2 = 4-bromo-N-(4-pyridylmethyl)-1,8-naphthalimide, L3 = 4-piperidin-N-(4-pyridylmethyl)-1,8-naphthalimide, have been synthesized and characterized by UV-Vis, multinuclear NMR, FT-IR and PXRD spectroscopic techniques. The crystal structures of all complexes have also been reported. The electrocatalytic activity of complexes is investigated under two catalysis conditions: (i) homogeneous conditions in acetonitrile using acetic acid (AcOH) as a proton source and (ii) heterogeneous conditions upon immobilization onto the surface of activated carbon cloth (CC). Complex 3 exhibited high electrocatalytic HER activity under both homogeneous and heterogeneous conditions. It catalyses proton reduction to molecular hydrogen in acetonitrile solution at a lower overpotential (640 mV) with a high turnover frequency (TOF) of 524.57 s-1 and demonstrates good stability in acidic conditions. Furthermore, catalytic (working) electrodes are prepared by immobilizing the complexes onto the surface of activated carbon cloth (CC) for electrocatalytic HER under heterogeneous conditions. An impressive HER performance was again obtained with catalytic electrode 3@CC in 1.0 M KOH, achieving a current density of -10 mA cm-2 at an overpotential of 262 mV. Chronoamperometric (CA) studies showed no significant decay of the initial current density for 10 h, indicating the excellent stability of 3@CC. Additionally, UV-Vis and NMR spectral studies of the recovered catalyst after electrocatalysis revealed no structural changes, demonstrating its robustness under reaction conditions.

Modulating the electronic structure of VS2via Ru decoration for an efficient pH-universal electrocatalytic hydrogen evolution reaction.

High-efficiency water electrolysis over a broad pH range is desirable but challenging. Herein, Ru-decorated VS2 on carbon cloth (Ru-VS2/CC) has been in situ synthesized, which features the regulated electronic structure of VS2 by introducing Ru. It is remarkable that the optimal Ru-VS2/CC displays excellent electrocatalytic hydrogen evolution activity with overpotentials of 89 and 87 mV at -10 mA cm-2 in 0.5 M H2SO4 and 1.0 M KOH, respectively. Theoretical calculations and electrocatalytic measurements have demonstrated that introducing Ru induces an enhanced charge density around the Fermi level, facilitating charge transfer and speeding up the electrocatalytic HER kinetics. The Gibbs free energy of the hydrogen intermediate (ΔGH*) of Ru-VS2/CC (0.23 eV) is much closer to zero than that of pure VS2 (0.51 eV) and Ru (-0.37 eV), demonstrating an easier hydrogen adsorption and desorption process for Ru-VS2/CC. The more favorable ΔGH*, differential charge density and the d-band center endow Ru-VS2 with enhanced intrinsic electrocatalytic activity. This study presents a feasible strategy for enhancing electrocatalytic HER activity by the regulation of the electronic structure and the rational integration of dual active components.

Ru Prussian blue analogue-derived Ru nanoparticles composited with a trace amount of Pt as an efficacious electrocatalyst for the hydrogen evolution reaction.

In this work, we designed a straightforward and highly reproducible synthetic methodology to prepare Ru0-Pt0 composites. We report a significant improvement in the electrocatalytic performance upon compositing Ru with a very trace amount of Pt. In particular, Ru nanoparticles were derived from a Ru-Prussian blue analogue (Ru PBA) and composited with (0.1, 0.5, and 1 mmol) metallic platinum following an optimized chemical reduction method. Interestingly, the composite with 0.5 mmol of Pt (Ru@C/Pt0.5) required low overpotentials of 32 and 140 mV to achieve current densities of 10 and 100 mA cm-2, respectively. Furthermore, Ru@C/Pt0.5 exhibited a smaller Tafel slope (26 mV dec-1), robust durability with 50 hours of long-term stability and a higher turnover frequency (TOF: 5.6 s-1@η10 mA cm-2) than commercial Pt/C (TOF: 4.1 s-1@η10 mA cm-2). First-principles calculations using density functional theory (DFT) revealed that the existence of Pt islands on the Ru nanoparticles weakened the strength of the adsorption of hydrogen at the Ru interstitials due to electrostatic repulsion caused by charge retention at Ru atoms near the corner of the islands, leading to rapid dissociation of hydrogen. This created a significant impact on the improvement of the electrocatalytic HER activity of the Ru@C/Pt0.5 electrocatalyst. It appears that restricting the concentration of Pt to trace amounts is a necessary condition for the observed catalytic efficiency, as the catalytic efficiency decreases with an increasing island size due to stronger binding of atomic hydrogen on peripheral Pt atoms and stabilization of adsorbed atomic hydrogen caused by softening of phonon modes with increasing island size. This study opens up a novel avenue for the exploration of highly efficient electrocatalysts for hydrogen evolution reactions.

Decoding Electrocatalysis: Transforming Aluminum-Clad TLC Plates into Potash Alum for Hydrogen Evolution Exploration

This work deals with using a waste aluminum-based TLC plate to prepare crystalline potash alum, which is subsequently activated for the study of hydrogen evolution reaction in alkaline KOH. The structural and morphological characterization of the synthesized potash alum (PA) has been assessed with powder X-ray diffraction and thermogravimetry analysis. Scanning electron micrographs reveal the morphology of the activated potash alum. The heterogeneous electrocatalytic HER activity in 1 M KOH attributes a moderate electrocatalytic efficiency for activated potash alum (APA) in the light of onset potentials, Faradic efficiency, double-layer capacitance, electrochemically activated surface area, and number of active sites. However, the electrocatalyst APA is a pre-catalyst as it undergoes a significant structural transformation under the electrochemical operation, leading to Al2O3 nanoparticles being the active catalyst for hydrogen production. Possibly, the chemical inertness of the Al2O3 induces a limitation in the local vicinity for the synergistic effect for facile electron transport in alkaline KOH.

Hierarchical Porous Activated Carbon from Wheat Bran Agro-Waste: Applications in Carbon Dioxide Capture, Dye Removal, Oxygen and Hydrogen Evolution Reactions.

This work reports an efficient method for facile synthesis of hierarchically porous carbon (WB-AC) utilizing wheat bran waste. Obtained carbon showed 2.47 mmol g-1 CO2 capture capacity with good CO2 /N2 selectivity and 27.35 to 29.90 kJ mol-1 isosteric heat of adsorption. Rapid removal of MO dye was observed with a capacity of ~555 mg g-1 . Moreover, WB-AC demonstrated a good OER activity with 0.35 V low overpotential at 5 mA cm-2 and a Tafel slope of 115 mV dec-1 . It also exhibited high electrocatalytic HER activity with 57 mV overpotential at 10 mA cm-2 and a Tafel slope of 82.6 mV dec-1 . The large SSA (757 m2 g-1 ) and total pore volume (0.3696 cm3 g-1 ) result from N2 activation contributing to selective CO2 uptake, high and rapid dye removal capacity and superior electrochemical activity (OER/HER), suggesting the use of WB-AC as cost effective adsorbent and metal free electrocatalyst.

Photocatalytic and electrocatalytic hydrogen production promoted by Nd/La substituted cobalt–nickel magnetic nanomaterials

The current work concentrates on the design of Nd/La doped Co0.7Ni0.3Fe2O4 nanocatalysts for the green, clean, and sustainable generation of hydrogen through overall photocatalytic and electrocatalytic water splitting routes using sol-gel auto-combustion route. The spinel symmetry with a Fd3m geometry and cubic polycrystalline nature was observed for the developed catalysts. Spherical formed agglomerated nanoparticles having average grain size of 127.10 and 120.08 nm was confirmed for the produced Co0.7Ni0.3Fe2O4 and Co0.7Ni0.3Nd0.02La0.02Fe1.96O4 catalysts through the FESEM results. Maximum saturation magnetization (Ms) of 64.81 emu/g and coercivity (Hc) of 1234.54 Oe were attained by undoped Co0.7Ni0.3Fe2O4 catalyst. This shows the superior magnetic behaviour of our prepared catalysts, for magnetic recording applications. The estimation of photocatalytic hydrogen production for the prepared photo nanocatalysts was conducted under ambient conditions, with an irradiation from a UV-visible light having wavelength range of 200–2400 nm. The prepared Co0.7Ni0.3Nd0.03La0.03Fe1.94O4 photocatalyst shows the maximum photocatalytic activity of 12.57 mmol gcat−1. Also, the photocatalytic hydrogen evolution, repeatability, and stability of all the prepared catalysts were analyzed at three successive cycles. The third cycle showed a little drop in photocatalytic hydrogen evolution to 11.26 mmol gcat−1 as compared to the first cycle. On the other hand, the electrocatalytic activity of produced electrocatalysts were determined towards the electrocatalytic HER via a three-electrode system in 0.5 M H2SO4 electrolyte. The produced Co0.7Ni0.3Nd0.03La0.03Fe1.94O4 nanocatalyst shows excellent electrocatalytic HER activity as compared to other samples. Hence, with photocatalytic/electrocatalytic water splitting traits, the prepared nanocatalysts are highly efficient and suitable for the production of clean and green hydrogen energy sources.

In‐Situ Growth of Cu2S‐MoS2 Bimetallic Electrocatalyst on Carbon Cloth for Hydrogen Evolution Reaction

AbstractHydrogen evolution reaction (HER) is one of prospective methods to produce hydrogen energy, and the key technology of which lies in the preparation of electrocatalysts. Preparations of catalysts with high efficiency, low price and good stability are expected. In this work, a new polyoxometalate‐based copper‐organic framework, [{CuII(C10N6H7)4(H2O)2}H6(PMo12O40)2] ⋅ 12H2O (1) [C10N6H7: 3‐(1H‐pyrazol‐4‐yl)‐5‐(pyridin‐4‐yl)‐1,2,4‐triazole], was synthesized as an electrocatalyst precursor, and confirmed by infrared spectroscopy (IR), single‐crystal X‐ray diffraction (SXRD) and X‐ray powder diffraction (PXRD). A new electrocatalyst (Cu2S‐MoS2@CC‐1) was synthesized from 1, thiourea (TU) and carbon cloth (CC) by a one‐pot hydrothermal method. Due to the synergistic effects between Cu2S and MoS2, the Cu2S‐MoS2@CC‐1 catalyst exhibits high electrocatalytic HER activity and good stability in 0.5 M H2SO4. Namely, Cu2S‐MoS2@CC‐1 shows low overpotential of 150 mV@10 mA cm−2 vs reversible hydrogen electrode (RHE) and small Tafel slope of 61 mV dec−1, and remains good stability at least 94 h and over 1000 catalytic cycles. This method provides a promising strategy for development of non‐noble metal catalysts.

Temperature controlled phase selective facile synthesis of tin sulfides and their electrochemical HER activity

Tin sulfide based semiconductors act as a promising candidate in photo/electro catalysis and solar cell applications owing to its suitable band gap and environment friendly nature. In this article we demonstrate a one-step synthesis of tin sulfides (SnS, SnS2, Sn2S3) via facile gas–solid reaction method. XRD, SEM and XPS analysis were carried out to characterize the samples for phase formation, morphology and valence states of the elements respectively. Bulk layered SnS and Sn2S3 micro-rods were obtained at the operating temperature of 700 °C and 600 °C respectively. Hexagonal nanoplate SnS2 was also obtained as a minor product during the synthesis of SnS. Furthermore, the electrocatalytic HER activity of the ballmilled SnS and Sn2S3 samples showed a considerable reduction in the overpotential of 171 mV and 126 mV respectively. The enhanced HER activity is attributed to the exposed catalytic active sites of the ballmilled samples.

Interface engineering of bifunctional nickel hydroxide/ nickel phosphide heterostructure for efficient intermittent hydrazine-assisted water splitting

Hydrazine oxidation reaction (HzOR) has been proposed to replace the sluggish oxygen evolution reaction (OER) for energy-saving hydrogen generation. However, the rational design of bifunctional electrocatalysts that can simultaneously accelerate HER/HzOR kinetics and the source of the hydrazine chemical substrate are still challenging. Herein, interfacial heterogeneous nickel hydroxide/nickel phosphide microstructures are in-situ grown on nickel foam (Ni(OH)2/Ni2P/NF) via a combined electrodeposition-phosphorization-electrodeposition strategy. After Ni(OH)2 modification, a charge redistribution is triggered between Ni(OH)2 and Ni2P, reducing the charge-transfer resistance and optimizing the adsorption energy of reaction intermediates. Ni(OH)2/Ni2P/NF thus yields an impressive bifunctional electrocatalytic activity for HER and HzOR with potentials of −72 and −14 mV at 10 mA cm−2, respectively. When using Ni(OH)2/Ni2P/NF as both electrodes, decreased cell voltage of 0.357 V is required to drive a current density of 100 mA cm−2 in 0.5 M hydrazine-containing alkaline electrolyte. Furthermore, an intermittent hydrazine-assisted water electrolysis system is proposed to make the combination of hydrazine sewage purification and energy-saving hydrogen production realistic.

Fabricating Ru single atoms and clusters on CoP for boosted hydrogen evolution reaction

Single atom catalysts (SATs) process the highest utilization efficiency of noble metals. The synergistic effect of noble single atoms and clusters, however, is insufficiently explored. In this work, Ru single atoms and clusters are fabricated on CoP substrate simultaneously, using a facile synchronous phosphorization method, with pre-prepared CoOOH and RuCl3 mixture as the raw materials. It is demonstrated that strong charge transfer is established between Co and Ru elements, which leads to electron-sufficient Ru sites. As a result, the Ru species decorated CoP exhibits excellent electrocatalytic activity for HER, with an overpotential of 32 mV to afford a current density of 10 mA/cm2 and a Tafel slope of 37.6 mV/dec, much better than the pure CoP counterpart. This work provides insights into the exploration of synergistic effect of noble metal single atoms and clusters fabricated on transition metal phosphide substrate.

A Double Atomic‐Tuned RuBi SAA/Bi@OG Nanostructure with Optimum Charge Redistribution for Efficient Hydrogen Evolution

AbstractCharge redistribution on surface of Ru nanoparticle can significantly affect electrocatalytic HER activity. Herein, a double atomic‐tuned RuBi SAA/Bi@OG nanostructure that features RuBi single‐atom alloy nanoparticle supported by Bi−O single‐site‐doped graphene was successfully developed by one‐step pyrolysis method. The alloyed Bi single atom and adjacent Bi−O single site in RuBi SAA/Bi@OG can synergistically manipulate electron transfer on Ru surface leading to optimum charge redistribution. Thus, the resulting RuBi SAA/Bi@OG exhibits superior alkaline HER activity. Its mass activity is up to 65000 mA mg−1 at an overpotential of 150 mV, which is 72.2 times as much as that of commercial Pt/C. DFT calculations reveal that the RuBi SAA/Bi@OG possesses the optimum charge redistribution, which is most beneficial to strengthen adsorption of water and weaken hydrogen‐adsorption free energy in HER process. This double atomic‐tuned strategy on surface charge redistribution of Ru nanoparticle opens a new way to develop highly efficient electrocatalysts.