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Heterogeneous structure supported Ni-Fe-P-Ni(OH) 2 /NF catalysts were fabricated by electroless deposition. The as-prepared composite catalyst exhibits remarkable electrocatalytic properties towards the hydrogen evolution reaction, requiring a low overpotential of 201 mV at a current density of −100 mA cm−2. Notably, the Ni-Fe-P-Ni(OH) 2 /NF also demonstrates exceptional oxygen evolution performance, achieving a current density of 100 mA cm−2 with only 294 mV overpotential. Moreover, its performance in overall water splitting, serving as both a cathode and an anode, showcases a significantly low overpotential of 1.51 V at a current density of 10 mA cm−2. Following a 24-hour chronopotentiometry stability test at a current density of 50 mA cm−2, the dual electrodes maintain excellent performance for overall water splitting. This work provides a feasible method for the research and development of efficient and stable overall water splitting catalysts. [Display omitted] • A heterogeneous Ni-Fe-P-Ni(OH) 2 /NF catalyst was prepared by electroless deposition. • Ni-Fe-P-Ni(OH) 2 /NF exhibited excellent HER catalytic activity (η 100 = 201 mV). • Ni-Fe-P-Ni(OH) 2 /NF exhibited remarkable OER catalytic activity (η 100 = 294 mV). • Ni-Fe-P-Ni(OH) 2 /NF (-) || Ni-Fe-P-Ni(OH) 2 /NF (+) displayed a low voltage of 1.51 V. • The catalyst exhibited remarkable stability of 50 h at 50 mA cm−2. [ABSTRACT FROM AUTHOR]

Exploring cost-effective electrocatalysts for the oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) have been a goal in the sustainable hydrogen-based society. Although abundant of alternative materials have been developed, Pt/C remains the most efficient electrocatalyst for the ORR and HER. Nevertheless, improving the stability and reducing Pt loading for Pt-based electrocatalysts are still big challenges. Herein, semiconductor crystals Na 4 Ge 9 O 20 with richer topology structure was chosen as electrocatalyst support, subsequently, the conductive polymer polyaniline (PANI) was decorated on semiconductor Na 4 Ge 9 O 20 , low-content Pt nanoparticles (Pt NPs) with the size of 1–3 nm were then uniformly anchored on the surface of Na 4 Ge 9 O 20 -PANI to obtain the efficient bifunctional electrocatalyst for ORR and HER in the acidic solution. More importantly, the stability and mass activity of the obtained electrocatalyst 5 wt% Pt/Na 4 Ge 9 O 20 -PNAI are significantly higher than that of commercial 20 wt% Pt/C for ORR and HER. It was proposed that the PANI could not only promote the electron transfer from Na 4 Ge 9 O 20 to Pt, but also stabilize the Pt NPs, thus, improving the electrocatalytic activity and stability of 5 wt% Pt/Na 4 Ge 9 O 20 -PNAI. • Low-content Pt nanoparticles with the size of 1–3 nm were uniformly anchored on the Na 4 Ge 9 O 20 -PANI. • The 5 wt% Pt/Na 4 Ge 9 O 20 -PANI afforded super electrocatalytic performance for HER and ORR. • The HER and ORR mass activities of the Pt/Na 4 Ge 9 O 20 -PNAI is about 3.5 and 2.7 times that of the commercial Pt/C. • The current density of Pt/Na 4 Ge 9 O 20 -PNAI is nearly unchanged in 20 h in HER. [ABSTRACT FROM AUTHOR]

Iron phosphides show promising but limited activity as hydrogen evolution reaction (HER) catalysts due to the low number of active sites and poor electroconductivity. Herein, iron phosphide nanosheets were synthesized and assembled to three‐dimensional structures for the first time via a physical‐vapor‐infiltration assisted hard template strategy. The 3D structured FePx nanosheet assembly exhibits excellent electrocatalytic performance for hydrogen evolution reaction over a wide pH range, outperforming most of the FePx catalysts reported to date in activity and exhibiting superior stability to the commercial Pt/C catalyst. Spectroscopic analyses and electrochemical results support that the fast electron transfer, increased active sites and expedited mass transport, due to the 3D structure of the FePx nanosheets, boost the HER performance. [ABSTRACT FROM AUTHOR]

[Display omitted] Developing multi-functional electrocatalysts is of great practical significance for fuel cells and water splitting. Herein, Rh-Rh 2 O 3 nanoclusters are prepared and the surface oxygen vacancy content is regulated elaborately by post-treatment. The optimized Rh-Rh 2 O 3 /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 μg Rh -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-Rh 2 O 3 /C-400 also displays promising performance in practical devices, with the H 2 -O 2 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. [ABSTRACT FROM AUTHOR]

Nickel iron bimetallic phosphide alloys are a promising electrocatalyst for oxygen evolution reaction (OER). In this work, a highly active Ni–Fe–P/Fe–Si heterojunction electrocatalyst for OER has been synthesized by one-step electrodeposition on iron plate. The synergism effect of Ni–Fe–P alloy and Fe–Si alloy particles after dealloying treatment promotes the construction of nanoflower-like heterogeneous structure with rich lattice defects and exposes a highly open multi-stage nanostructure surface. Furthermore, Si induced the localized electron redistribution optimizes catalytic performance by accelerating electron transfer. The optimal Ni–Fe–P/Fe–Si OER catalyst requires a much low overpotential of 209 mV at a current density of 10 mA cm−2, and 270 mV at a current density of 200 mA cm−2. The prepared Ni–Fe–P/Fe–Si electrode can maintain a current density of 10 mA cm−2 within 24 h, which shows significant electrochemical stability. This study provides a new prospect for the preparation of cost-effective heterogeneous catalysts. [Display omitted] • A new nanoflower shaped heterogeneous electrocatalyst: Ni–Fe–P/Fe–Si. • A excellent electrocatalytic activity of OER: 209 mV/10 mA cm−2 in 1 M KOH. • A new strategy design high activity and low-cost electrocatalysts. [ABSTRACT FROM AUTHOR]

The proper construction of high efficiency, low-cost, earth-abundant oxygen evolution reaction (OER) catalyst is essential for hydrogen formation by water splitting. A novel electrocatalyst with highly active OER performance was manufactured by a simple electroless deposition method of Ni-Fe-P-WO 3 on nickel foam (NF). Benefiting from outstanding mass transfer capability of Ni-Fe-P-WO 3 /NF heterogeneous structure, abundance of active sites in the amorphous architecture and etc., the Ni-Fe-P-WO 3 /NF shows extremely superb electrocatalytic properties compare to noble metal catalyst IrO 2 /NF for OER, which needs an overpotential of only 218 mV in 1.0 M KOH solution to achieve the current density of 10 mA cm−2. It also has remarkable OER activity at high current density that only needs 298 mV to attain 100 mA cm−2 current density. Moreover, the Ni-Fe-P-WO 3 /NF has low Tafel slope of 42 mV dec−1. This study offers a novel approach to the production of OER multiphase electrocatalysts from oxides and alloys. [Display omitted] • The Ni-Fe-P-WO 3 /NF electrode is synthesized by a facile electroless deposition method. • The Ni-Fe-P-WO 3 /NF exhibits excellent performances for OER: 218 mV at 10 mA cm−2 in 1 M KOH. • Interfacial effect of heterogeneous structures and synergistic effect between metals. [ABSTRACT FROM AUTHOR]

Electrocatalytic nitrate reduction to ammonia is an attractive alternative route for the traditional Haber-Bosch process, yet suffers from unsatisfied efficiency and selectivity due to multiple intermediates as well as the competitive hydrogen evolution reaction. Herein, we report a defect-rich AuCu@Ag nanowires (AuCu@Ag NWs) with exclusive strain effect as an efficient electrocatalyst for nitrate reduction reaction (NO 3 –RR). AuCu@Ag NWs catalyst shows excellent electrocatalytic performance for NO 3 – to NH 3 in the NO 3 –RR process, with the NH 3 yield rate of 975.1 μg h−1 mg−1 cat. , Faraday efficiency of 96.9% and NH 3 selectivity of 95.7%. DFT theoretical investigation manifests that the Ag atomic shell deposited layer-by-layer on AuCu NWs generates exclusive strain effect that accelerates the adsorption of NO 3 – and reaction intermediates, thereby enhances the NO 3 –RR activity. This work opens up new avenues for rational construction of high-performance NO 3 –RR electrocatalysts by synergistically modulating the electronic configuration of the active atoms through defect and strain engineering. [Display omitted] • AuCu@Ag nanowires were prepared by defect engineering and strain engineering. • The catalysts possess compositional coordination effect and the exclusive strain effect. • The catalysts exhibit excellent performance for nitrate reduction reaction. • This work constructs a unique core-shell structured material. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel nested heterogenous structure of Ni-Fe-P/Co-W. • A specific electronic structure brought by the synergistic action of five elements of Ni-Fe-P/Co-W. • A remarkable electrochemical performance of Ni-Fe-P/Co-W, and the required overall water splitting overpotential only 1.46 V for 10 mA cm−2 in 1 M KOH. Recently, the application of multi-component transition alloy catalysts in the water splitting field has been a popular development trend. In this work, we have proposed a multi-alloy catalyst for in-situ synthesis of nested multilayer heterostructure Co-W on Ni-Fe-P by electrodeposition way. The heterogeneous interfaces brought by the nested heterogenous structure expose abundant active sites on the catalyst, effectively enhancing the catalytic performance. Moreover, the synergistic effect of five elements (Ni, Fe, P, Co, and W) in the electrocatalysts improves electron transfer efficiently. By adjusting the proportion of Co and W of Co-W-O in the Ni-Fe-P plating solution, we have obtained optimal electrochemical performance in 1 M KOH solution. At 150 (10) mA cm−2, the HER and OER overpotentials are 157.6 (23.6) mV and 260.6 (219.9) mV respectively. Furthermore, it shows a low cell voltage (1.46 V) in overall water splitting, exceeding most of the previously reported electrocatalysts. The activity of Ni-Fe-P/Co-W has no significant decrease at 100 mA cm−2 for 100 h. Subsequently, XPS and Raman spectroscopy are used to infer the mechanism of the electrochemical reaction. This study demonstrates a kind of simple, scalable, and efficient bifunctional electrocatalyst method that has special nested heterogenous structure for overall water splitting. [ABSTRACT FROM AUTHOR]

A new type of superior activity and highly cost-effective amorphous electrocatalyst Co–Mo–Fe on nickel foam (NF) supports is prepared by facile one-step rapid electrodeposition. The amorphous electrocatalyst Co–Mo–Fe/NF shows excellent oxygen evolution reaction (OER) performance, with a small overpotential of 218 mV at 10 mA cm−2 current density in 1 M KOH. It only needs overpotential of 252 mV at 50 mA cm−2 current density in 1 M KOH, and the Tafel slope is 45 mV dec−1. The results show that the doping of Fe significantly improves the oxygen evolution capacity of the Co–Mo–Fe system. The synergistic effect of the three metals and the doping of the third metal iron make the oxygen evolution active sites of the whole system increase significantly. This provides a feasible direction for the oxygen evolution reaction of cobalt transition metal. • The amorphous Co–Mo–Fe is synthesized by a facile electrodeposition method. • The Co–Mo–Fe has excellent electrocatalytic performance for oxygen evolution reaction. • The excellent oxygen evolution performance of Co–Mo–Fe promotes the process of hydrogen production from water splitting. • The addition of Fe to Co–Mo–Fe adjusts the structure and improves the synergistic effect of the three metals. [ABSTRACT FROM AUTHOR]

Bi-functional crystalline/amorphous Pt/MoO 3-x interfaces have been successfully constructed via a facile polyoxometalate-assisted in-situ synthesis protocol, which achieve a cell voltage of only 55/238 mV at 10/100 mA cm−2 for overall hydrazine-seawater splitting, 1.584/1.543 V lower than that for conventional overall seawater splitting. [Display omitted] • First construction of bi-functional crystalline/amorphous interface in Pt/MoO 3-x nanosheets. • The resultant catalyst exhibits superior HER/HzOR activities surpassing commercial Pt/C. • The observed HER/HzOR working potential is only –23/-41 mV at 10 mA cm−2 in seawater. • The electrolyzer requires a cell voltage of only 55/238 mV to gain 10/100 mA cm−2. • Crystalline/amorphous Pt/MoO 3-x interfaces possess optimized d -electron configurations for HER/HzOR. Hydrazine-assisted water electrolysis is a promising energy-efficient strategy for hydrogen production. Nonetheless, developing high-performance bi-functional electrocatalysts towards both hydrogen evolution reaction (HER) and hydrazine oxidation reaction (HzOR) remains great challenges, especially for hydrazine-seawater splitting. Herein, we report a polyoxometalate-assisted in-situ synthesis protocol for constructing bi-functional crystalline/amorphous Pt/MoO 3-x interfaces toward both efficient HER and HzOR. The polyoxometalate-derived crystalline/amorphous Pt/MoO 3-x interfaces deliver working potentials of only –23 and −41 mV at 10 mA cm−2 for HER and HzOR in seawater electrolyte, respectively. Meanwhile, ultrahigh mass activities of 38.39 A mg Pt -1 for HER at −100 mV potential and 23.84 A mg Pt -1 for HzOR at 50 mV potential are also achieved, over 30.2 and 52.9 times higher than those of commercial Pt/C. As bi-functional electrocatalysts for overall hydrazine-seawater splitting, the electrolyzer requires a cell voltage of only 55/238 mV at 10/100 mA cm−2, 1.584/1.543 V lower than that of the seawater splitting system. Moreover, a proof-of-concept self-powered hydrazine-seawater electrolysis system driven by direct hydrazine fuel cell is further demonstrated, which achieves a hydrogen production rate of 0.29 mL cm−2 min−1. DFT calculations verify that, the crystalline/amorphous interfaces endow Pt/MoO 3-x an optimized d -electron configuration with favorable H* adsorption and promoted dehydrogenation kinetics of *N 2 H 4 to *N 2 H 3 in the potential-determining step. This work provides a novel strategy and inspiration toward the design of efficient bi-functional electrocatalysts for hydrazine-assisted hydrogen production from seawater. [ABSTRACT FROM AUTHOR]

Visible-light-driven photocatalytic hydrogen evolution is considered as one of the most useful approaches to produce renewable fuels from abundant resources. Indium oxide (In 2 O 3) has attracted much attention in the field of solar hydrogen production due to its moderate band gap, which can be driven by visible light easily. However, the efficiency of hydrogen evolution reaction (HER) of In 2 O 3 is currently unsatisfactory. To enhance the HER efficiency of In 2 O 3 , herein, sandwich-structured In 2 O 3 /ZnIn 2 S 4 heterostructure was precisely constructed via in-situ growth of ZnIn 2 S 4 nanosheets on the In 2 O 3 hollow fibers. The fabricated In 2 O 3 /ZnIn 2 S 4 heterostructure exhibited a significantly enhanced photocatalytic HER activity of 2.18 mmol/g/h as compared to pure In 2 O 3 and ZnIn 2 S 4. Such efficient photocatalytic hydrogen production is attributed to the tightly-bound interface between (001) planes of flake ZnIn 2 S 4 and (222) planes of In 2 O 3. Experimental and theoretical investigation indicates compactly interface enabling efficient charge transfer and separation, which benefited the excellent photocatalytic HER performance. [Display omitted] ● In 2 O 3 hollow fibers derived from alginate fibers were used to construct In 2 O 3 /ZnIn 2 S 4 heterostructure. ● Tightly-bound interface between In 2 O 3 (222) and ZnIn 2 S 4 (001) facilitated charge transfer for outstanding hydrogen production. ● In 2 O 3 /ZnIn 2 S 4 achieved a photocatalytic hydrogen evolution rate of 2.18 mmol/g/h under visible light irradiation. [ABSTRACT FROM AUTHOR]

The sluggish kinetics of the four-electron-proton coupled oxygen evolution reaction (OER) limits the efficiency of water splitting. Herein, Ni–S–CoFe 2 O 4 magnetic nanosheets supported on Ni Foam (Magn-Ni-S-CoFe 2 O 4 /NF) as highly active OER electrocatalysts are synthesized via an extremely simple magnetic-field guided co-electrodeposition strategy. With the application of magnetic fields, the flower-like structures consisting of numerous nanosheets are obtained. This special interconnected structure can effectively reduce the transfer resistance to electrons during catalysis. The ultra-thin amorphous Ni–S layer at the edge of well-defined crystalline CoFe 2 O 4 provides more active sites for the reaction because of the abundant defects, which greatly enhances the OER performance. At the same time, the application of magnetic fields changes the chemical state of the electrocatalyst. The well-designed Magn-Ni-S-CoFe 2 O 4 /NF exhibits excellent OER activity with a low overpotential of 228 mV at the current density of 10 mA cm−2, which is lower than the value of 253 mV for the Ni–S–CoFe 2 O 4 /NF without applied magnetic field, a small Tafel slope of 72 mV dec−1 and excellent stability for at least 24 h. This work provides a simple magnetic field-assisted synthesis method to prepare electrocatalysts with excellent OER activity. • A new highly active and cost-effective electrocatalyst: Magn-Ni-S-CoFe 2 O 4 /NF. • An innovative synthesis method: electrodeposition assisted by magnetic field. • A excellent electrocatalytic activity of OER: 228 mV/10 mA cm−2 in 1 M KOH. [ABSTRACT FROM AUTHOR]

The development of highly efficient and superior durability electrocatalysts is vital to expedite hydrogen evolution reaction (HER). Herein, a mixed amorphous and nano-crystalline Ni–Co–Fe–P alloy on Ni foam after 75 s dealloying in 3 M HCl (Ni–Co–Fe–P/NF-3-75) is synthesized by the preparation strategy of two-step method consisting of electroless deposition and dealloying process. Ni–Co–Fe–P/NF-3-75 shows an excellent HER performance and high durability in both alkaline and neutral conditions by optimizing the composition of the catalysts, acid concentration, and the time of dealloying. Benefitting from the high conductivity of Ni foam carrier, coordination between polymetallic phases, and the large exposure of defects, the as-prepared Ni–Co–Fe–P/NF-3-75 requires only a low overpotential of 56 mV and 104 mV to reach the current density of 10 mA cm−2 in 1.0 M KOH and 1.0 M phosphate buffer (PBS), respectively. Remarkably, the Ni–Co–Fe–P/NF-3-75 electrode exhibits superior cycling stability and long-term robust durability without obvious overpotential decline. The successful preparation of the Ni–Co–Fe–P/NF-3-75 catalyst indicates that this method provides an efficient way to synthesize polymetallic phosphides for hydrogen evolution reaction. Image 1 • The Ni–Co–Fe–P/NF was synthesized by facile electroless plating and fast dealloying. • Dealloying process is an efficient method to increase the ECSA for HER. • The Ni–Co–Fe–P/NF-3-75 exhibit a mixed amorphous and nano-crystalline structures. • The P atomic ratio of Ni–Co–Fe–P/NF catalysts is related to the HER activity. • The Ni–Co–Fe–P/NF-3-75 deliver superior HER activity in alkaline and neutral medium. [ABSTRACT FROM AUTHOR]

Establishing efficient co-catalytic loaded semiconductors for efficient charge separation is a hopeful way for enhance photocatalytic water splitting hydrogen evolution. Herein, we successfully constructed the Cd 0.5 Zn 0.5 S/Ni 2 P (CZS/Ni 2 P) nanocomposites via two-step hydrothermal method. The CZS/Ni 2 P composites show much improved activity than the origin CZS for photocatalytic H 2 generation. When the content of Ni 2 P loaded on the Cd 0.5 Zn 0.5 S (CZS) is 0.3 mol%, the photocatalyst achieves the highest photocatalytic hydrogen generation rate of 41.26 mmol g−1 h−1 under visible light. The Ni–S bonds on the close contact interface between CZS and Ni 2 P can be act as electron-bridge to provide a channel for electron transfer. During the photocatalysis processing, Ni 2 P can be used as electron traps to attract electrons from CZS, resulting in the improvement of the photocatalytic performance. • A novel noble-metal-free CZS/Ni 2 P photocatalyst via two-step hydrothermal method. • The CZS/Ni 2 P photocatalyst boosts photocatalytic hydrogen evolution. • The Ni–S bonds can effectively promote the charge transfer and separation of CZS. • The effect of Ni 2 P amounts on photocatalytic performance was investigated. • The highest H2 evolution rate (41.26 mmol g−1 h−1) from the optimum composition. [ABSTRACT FROM AUTHOR]

Distributed production of hydrogen peroxide (H 2 O 2) via 2e-oxygen reduction reaction (ORR) has gained significant attention as a green and safe approach. In this work, black liquor-derived carbon is for the first time functionalized as an electrocatalyst for efficient H 2 O 2 production. The oxygen and boron co-functionalized porous activated carbon (C 3 -O 3 -B 10) exhibits high activity with almost zero overpotential for 2e-ORR, satisfactory H 2 O 2 selectivity (77 %) and good stability. Mechanism investigations reveal that C 3 -O 3 -B 10 favors catalyzing the 2e-ORR both thermodynamically and kinetically, with a low Tafel slope of 65 mV dec−1, fast charge transfer ability, and low apparent activation energy of 6.7 kJ mol−1 @ 0.4 V RHE , owing to the presence of abundant active C O and B-C 2 -O functional groups. This work demonstrates that the functionalized black liquor-derived carbon is a reliable and sustainable electrocatalyst to produce H 2 O 2 via ORR, which provides new clues for the utilization of black liquor waste resources in the field of energy conversion and storage. • Black liquor is used as the raw material to prepare a functionalized porous carbon compound. • BL-derived carbon is highly active to catalyze the 2e-oxygen reduction reaction to produce H 2 O 2. • Almost zero overpotential for 2e-ORR, satisfactory H 2 O 2 selectivity and good stability. • Low Tafel slope of 65 mV dec−1, fast charge transfer, low apparent activation energy of 6.7 kJ mol−1. • Abundant active C O and B-C 2 -O functional groups are responsible for superior performance. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ru nanoclusters are sandwiched between TiO/TiO 2 nanosheet and carbon coating layer. • Ru-TiO/TiO 2 @NC shows superior activity for alkaline HOR/HER as compared to Pt/C. • The anti-passivation ability of Ru-TiO/TiO 2 @NC is significantly enhanced. • The adsorption of H ad /OH ad intermediates is decoupled and optimized on Ru and TiO/TiO 2 sites. • The role of TiO/TiO 2 and carbon coating layer is demonstrated and discussed. Developing active and stable non-Pt electrocatalysts for hydrogen oxidation (HOR) and evolution reactions (HER) are critical for anion exchange membrane fuel cells and water electrolyzers. Herein, we report a highly active and robust electrocatalyst Ru-TiO/TiO 2 @NC, in which Ru nanoclusters are sandwiched between TiO/TiO 2 nanosheets and nitrogen-doped carbon layers. Taking advantage of both the optimized Ru-TiO/TiO 2 interaction and the conductive carbon coating layers, the Ru-TiO/TiO 2 @NC exhibits both exceptional HOR/HER activity and superior stability, outperforming Pt/C in the alkaline solution. The HOR mass activity reaches up to 107.2 A g Ru -1 at an overpotential of 50 mV, and the specific exchange current density is 0.271 mA cm−2. The HER overpotential at 10 mA cm−2 is only 39 mV, 34 mV lower than required by Pt/C. More importantly, the Ru-based catalyst exhibits excellent anti-oxidation ability by virtue of the unique sandwich structure. Density functional theory calculations discover that the d-band center of Ru in Ru-TiO/TiO 2 is downshifted by 0.29 eV compared to Ru-TiO 2 , decoupling and optimizing the H ad /OH ad adsorption on Ru, i.e., H ad is promoted, while OH ad is inhibited and transferred to TiO/TiO 2. As a result, (i) the energy required by the potential determining step of HOR/HER is lowered, and (ii) the anti-oxidation ability of the Ru-TiO/TiO 2 is enhanced. This work not only addresses the issue of Ru passivation at high anode potentials but also provides an innovative and versatile approach to designing advanced electrocatalysts. [ABSTRACT FROM AUTHOR]

Establishing efficient nano-porous electrocatalysts for facilitating electron transfer is a one of the useful ways for enhance water splitting. Herein, Ni-Fe-Cu-Co-W high entropy alloy (NFCCW-HEA) electrocatalysts on the iron sheet substrate have been successfully prepared by a simple and efficient one-step electrodeposition method. High entropy alloys have a variety of active sites and unique atomic scale synergies, which makes the catalyst have good catalytic performance and stability. Meanwhile, the HEA coating like cauliflower by electrodeposition can provide more attachment sites, and significantly upgrade the OER catalytic activity. NFCCW-HEA catalysts exhibit an excellent overpotential of 247.3 mV under the current density of 10 mA·cm−2, and a low Tafel slope of 62.9 mV dec−1. The electrocatalyst shows long term stability of electrolysis for over 24 h in 1 mol·L−1 KOH alkaline solution, which shows good stability. We expect to provide a new idea for the preparation of nano porous high entropy alloy electrocatalysts by one-step electrodeposition technology. [Display omitted] • The nano-porous Ni-Fe-Cu-Co-W high entropy alloy electrocatalysts are prepared by a simple and efficient one-step electrodeposition method. • The formation mechanism of catalysts is carefully studied. • The unique cauliflower like nano-sheets can significantly improve the OER catalytic performance. • The synergy of multiple components • Explore different active sites [ABSTRACT FROM AUTHOR]

Er-MoO 2 with modulated electronic structure was successfully fabricated via a facile method. The obtained Er-MoO 2 exhibits superior overall seawater splitting, achieving a cell voltage of 1.67 V at 10 mA cm−2. A Mg/seawater battery fabricated with the Er-MoO 2 cathode displaying a peak power density of 8.17 mW cm−2 and an excellent discharge stability. [Display omitted] • Demonstration of a rational design of Er-MoO 2 with modulated electronic structure. • Optimized Er-MoO 2 demonstrates superior overall water/seawater splitting performances. • Er-MoO 2 delivers a cell voltage of 1.67 V at 10 mA cm−2 for overall seawater splitting. • Mg/seawater battery with Er-MoO 2 cathode achieves a peak power density of 8.17 mW cm−2. Electronic structure modulation is an effective strategy for electrocatalysts to boost their hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) activities in water splitting. Here, a rational design of rare earth element Er-doped MoO 2 (Er-MoO 2) with modulated electronic structure is reported, leading to boosted water splitting activity in both alkaline and seawater electrolyte. Experimental results manifest that the optimized Er-MoO 2 requires overpotentials of only 94/221 mV and 173/312 mV to deliver the 10 mA cm−2 for HER/OER in alkaline and seawater electrolyte, respectively. As bifunctional electrocatalysts for overall water splitting, the Er-MoO 2 requires a cell voltage of only 1.52 and 1.67 V to gain 10 mA cm−2 in alkaline and seawater electrolyte, respectively. Moreover, a Mg/seawater battery coupled with the Er-MoO 2 cathode achieves a maximum power density of 8.17 mW cm−2, combining with an excellent discharging stability for at least 24 h. This work provides a facile strategy toward the design of efficient non-noble metal catalysts for overall water/seawater splitting and Mg/seawater battery. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel core-shell structured Pt@NC/C catalyst is synthesized. • Pt@NC/C shows accelerated HOR kinetics in the alkaline media. • Pt@NC/C has excellent anti-CO ability. • Hydroxyl adsorption is enhanced on the carbon layer covered Pt. Improving the CO-tolerant ability of Pt-based electrocatalysts is crucial for fuel cells fed with industrial byproduct hydrogen. Herein, we present a novel core-shell structured Pt@NC/C catalyst consisting of ultrafine Pt nanoparticles (1.63 nm) as the core and ultrathin nitrogen-doped carbon layers (0.36 nm) as the shell. The catalyst exhibits excellent alkaline hydrogen oxidation reaction (HOR) activity with a mass activity of 187 A g−1 Pt and a specific activity of 0.20 mA cm−2 Pt , which are 1.3 and 2.2-folds to the counterpart Pt/C, respectively. More remarkably, it shows good anti CO-poisoning ability. In presence of H 2 with 100 ppm CO, the HOR current degraded by 18.22% on 10% Pt/C versus only 4.81% on 10% Pt@NC/C-400. The combined X-ray photo-electron spectrum (XPS) analysis, CO ad stripping, CO oxidation and Zeta potential measurements imply that hydroxyl adsorption is enhanced on the NC covered Pt in 10% Pt@NC/C-400 possibly due to electron modulation induced by the strong metal and support interaction, which accelerates HOR kinetics and improvs anti-CO ability. This work provides a facile and feasible strategy to design efficient and CO-resistant Pt-based catalysts. [ABSTRACT FROM AUTHOR]

A proof-of-concept photo-assisted Mg/H 2 O battery is successfully designed, which enables the simultaneous conversion of photo- and chemical energy into electric and hydrogen energy, delivering a peak power density of 1.18 mW cm−2 and hydrogen production rate of 0.56 mL cm−2 min−1 under illumination. [Display omitted] • First demonstration of photo-assisted Mg/H 2 O battery for simultaneous generation of electricity and hydrogen. • CuSCN hole-storage layer facilitates the photo-charge separation and suppresses photo-oxidation of Cu 2 O. • CuSCN/Cu 2 O photocathode displays a photocurrent density over 1.7 times higher than that of Cu 2 O. • The peak power density and hydrogen production rate for this battery are 3.6 and 9.6 times higher than those in dark. A seawater-electrolyte Mg/H 2 O battery, converting chemical energy of Mg into electricity and hydrogen via anodic/chemical oxidation of Mg and cathodic reduction of water, combines electricity generation and H 2 production, thus is not only ideal power source for marine equipment, but also intriguing on-line/offshore H 2 generator for fuel cells. Nonetheless, it substantially suffers from the slow kinetics of hydrogen evolution reaction at the cathode. Herein, we propose a proof-of-concept design of a photo-assisted Mg/H 2 O battery with simulated seawater (0.5 M NaCl, pH = 6.8) as the electrolyte, and a CuSCN/Cu 2 O photocathode is applied to promote the hydrogen evolution reaction kinetics and battery performance. Under illumination, the CuSCN/Cu 2 O reveals a photocurrent density of up to 4.32 mA cm−2 at 0 V vs reversible hydrogen electrode, over 1.7 times higher than that of Cu 2 O. A photo-assisted Mg/H 2 O battery is demonstrated with a peak power density of 1.18 mW cm−2 and a H 2 production rate of 0.56 mL cm−2 min−1 under illumination, which is 3.6 and 9.6 times higher than those obtained in the dark. This novel strategy of a photo-assisted Mg/H 2 O battery enables the simultaneous conversion of photo- and chemical energy into electric energy and hydrogen from seawater. [ABSTRACT FROM AUTHOR]

[Display omitted] • A unique Ni/Ru hetero-nano-twin catalyst with rich interfaces. • Electron re-distribution at interfaces of Ni/Ru twins balances H ad /OH ad adsorption. • Ni 1 Ru 1 twin shows superior activity for alkaline HOR/HER as compared to Pt/C. • Ni 1 Ru 1 twin is remarkably stable with a break-down potential up to 0.25 V RHE. • The crucial role of the intimate Ni/Ru nano-twin is demonstrated and discussed. Herein, unique Ni-Ru nano-twins (Ni 1 Ru 1 /C) are reported for the first time as a superior bifunctional catalyst for hydrogen oxidation/hydrogen evolution reaction (HOR/HER). Compared to Pt/C, the Ni 1 Ru 1 /C nano-twins display a remarkable HOR activity with a comparable mass activity of 0.12Amg−1 metal and superior HER activity, with an overpotential (դ) of only 16 mV for achieving a cathodic HER current of 10mAcm−2, together with a high turnover-frequency of 1.88 s−1 (@դ=30 mV). Additionally, the HOR limiting current of the Ni 1 Ru 1 /C nano-twins can be maintained up to a break-down potential of 0.25V RHE , demonstrating excellent electrochemical stability. Experimental and theoretical studies reveal that the electron re-distribution at the Ni/Ru interface of Ni-Ru nano-twins optimizes the binding energy of the adsorbed hydrogen (H ad) and the adsorbed hydroxyl (OH ad) intermediates, allowing the HOR/HER to proceed via a low energy barrier. This work provides a strategy to synthesize hetero-metal nano-twins as promising multi-functional catalysts and highlights the critical role of interfaces for heterostructured electrocatalysts. [ABSTRACT FROM AUTHOR]

A Mg/seawater battery driven seawater electrolysis hydrogen production system based on a Ni/V 2 O 3 Schottky electrode is successfully demonstrated, achieving a total hydrogen production rate of 12.42 mL cm−2 h−1 from natural seawater with a high Mg-to-H 2 conversion efficiency up to 80.87%. [Display omitted] • Demonstration of a self-powered system for sustainable generation of hydrogen from seawater. • The tailored Ni/V 2 O 3 Schottky electrode exhibits remarkable HER activity in seawater. • The fabricated Mg/seawater battery delivers a peak power density of 17.81 mW cm−2. • The self-powered system yields a hydrogen production rate up to 12.42 mL cm−2 h−1 from seawater. Developing novel and efficient techniques for extracting hydrogen from natural seawater sustainably via electrolysis is highly attractive, yet remains a great challenge. Herein, a self-powered electrolysis system (SPES) driven by Mg/seawater batteries (MSBs) with a Ni/V 2 O 3 Schottky electrode is demonstrated for sustainable production of hydrogen from seawater. The Ni/V 2 O 3 Schottky electrode is constructed to serve as the hydrogen evolution reaction (HER) cathode for both the MSBs and seawater electrolysis unit in the SPES, enabling facile seawater HER with 10 and 1000 mA cm−2 at low overpotential of 176 and 649 mV respectively. The MSB with the Ni/V 2 O 3 Schottky cathode delivers a peak power density up to 17.81 mW cm−2. Importantly, the designed SPES achieves a high hydrogen production rate up to 12.42 mL cm−2 h−1 from natural seawater with a high energy conversion efficiency of 80.87 %. This work offers an intriguing technique for in-situ sustainable acquisition of hydrogen from natural seawater. [ABSTRACT FROM AUTHOR]

• A multistage morphology Ni-Fe-P-Ni 3 S 2 /NF heterogeneous electorcatalyst. • A simple synthesis method: electroless composite deposition. • A excellent electrocatalytic activity of HER and OER: 65 and 219 mV at 10 mA cm−2 in 1 M KOH. Exploring high-performance noble-metal-free bifunctional electrocatalysts is vitally crucial for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in water electrolysis. Herein, the defect-enriched multistage morphology Ni-Fe-P-Ni 3 S 2 heterogeneous catalyst growth on the Ni Foam (Ni-Fe-P-Ni 3 S 2 /NF) is synthesized for the first time through electroless composite plating. Attributed to the heterogeneous structure between Ni-Fe-P alloys and Ni 3 S 2 , abundant lattice defects, exposed highly open multistage skeleton morphology, the optimal Ni-Fe-P-Ni 3 S 2 /NF catalyst only requires 65 and 219 mV to reach the current density of 10 mA cm−2 towards HER and OER in alkaline solution, respectively. With regard to the overall water splitting, the alkaline electrolyzer assembled by Ni-Fe-P-Ni 3 S 2 /NF electrodes exhibits a low cell voltage of 1.5 V at 10 mA cm−2. This research provides a new perspective for the preparation of heterogeneous catalysts between alloys and sulfides for overall water splitting. [ABSTRACT FROM AUTHOR]

NiFeMo hybrid film prepared by simple one-step electrodeposition can act as cathode and anode materials in an electrolytic cell for urea electrolysis to hydrogen generation and purification of wastewater containing urea. [Display omitted] • The NiFeMo hybrid film is synthesized by a facile one-step electrodeposition method. • The NiFeMo exhibits excellent performances for HER and UOR toward urea electrolysis. • The OER activity of NiFeMo facilitates H 2 production in varying urea concentration. • Mo dopant induced charge redistribution and synergistic effect between three metals. Urea electrolysis as a promising approach to highly effective and energy-saving hydrogen production, is gaining increasing attention to cope with the global energy crisis and environmental issues. In this study, we report a NiFeMo hybrid film acting as cathode and anode materials in an electrolytic cell for urea electrolysis to hydrogen generation and purification of wastewater containing urea. The NiFeMo prepared by simple one-step electrodeposition exhibits excellent electrocatalytic performances for hydrogen evolution reaction (HER) and urea oxidation reaction (UOR). Meanwhile, the excellent oxygen evolution reaction (OER) activity of NiFeMo can ensure the smooth progress of hydrogen production in the wastewater of varying urea concentration. The results show that Mo dopant has significant effects on HER performance of the NiFeMo. The excellent OER and UOR performance of the NiFeMo is derived from synergism of these three metals and the formation of active intermediates. This work provides a facile method to synthesize low-cost and high-performance electrocatalysts for urea electrolysis and water splitting, which may open up new opportunities for hydrogen production. [ABSTRACT FROM AUTHOR]

Hydrogen evolution reaction (HER), serving as the cathodic reaction of magnesium (Mg)/seawater battery, could not only produce clean hydrogen directly from seawater but also generate electricity. However, the kinetics of the hydrogen evolution directly from the neutral seawater is sluggish, and leads to unsatisfied HER and battery performance. Herein, a unique porous CoP/Co 2 P heterostructure electrode was fabricated via a template-free strategy. As demonstrated, the optimized porous CoP/Co 2 P heterostructure exhibits superior activity for HER, with low overpotential of 87, 133 and 454 mV at 10 mA cm−2 in acidic, alkaline and seawater media, respectively. An Mg/seawater battery fabricated with the porous CoP/Co 2 P heterostructure cathode displays promising performance, with a peak power density of 6.28 mW cm−2, approaching to the platinum cathode, and a satisfied stability in a 24 h stability test, which is the best non-noble metal cathode reported. The superior battery performance could be attributed to the large active interfaces and the high specific surface area of the porous CoP/Co 2 P heterostructure electrode, which guarantee a low polarization of the cathodic HER. • The first demonstration of template-free synthesis porous CoP/Co 2 P heterostructure. • CoP/Co 2 P heterostructure is featured with porous structure and abundant interfaces. • CoP/Co 2 P heterostructure exhibits high HER and Mg/seawater battery performance. [ABSTRACT FROM AUTHOR]

Heterostructure plays significant roles in many photocatalytic reactions, as it can provide more efficient route for the charge carrier separation and transferring. Herein, we report a rational design of a new kind of photocatalyst, in which SrTiO 3 -T/Cd 0.5 Zn 0.5 S heterostructure is prepared via a simple hydrothermal method. SrTiO 3 with oxygen vacancy is prepared by a controllable solid-state reaction of NaBH 4 and SrTiO 3 nanocrystals. The oxygen vacancies on the surface of SrTiO 3 can be used as electron traps to attract electrons from Cd 0.5 Zn 0.5 S and provide proton reduction sites for H 2 production during the photocatalysis processing, thereby effectively inhibit the recombination of electron-hole pairs. It has demonstrated that SrTiO 3 -T/Cd 0.5 Zn 0.5 S nanocomposites can achieve the highest photocatalytic hydrogen evolution rate of 25.01 mmol g−1 h−1 under visible light, which is about 2 times than that of the original Cd 0.5 Zn 0.5 S. • A novel STO-T/CZS photocatalyst via a simple hydrothermal method. • The STO-T/CZS heterostructure boosts photocatalytic H 2 evolution. • The STO with oxygen vacancy was fabricated by a solid-state reaction. • The mechanism for photocatalytic H 2 -production was proposed. [ABSTRACT FROM AUTHOR]

One of the main challenges for electrochemical water splitting is to develop low-cost and efficient oxygen evolution anode materials. In this work, the Co–P alloys as efficient electrocatalysts for oxygen evolution reaction in alkaline media have been successfully synthesized by using electroless plating under mild conditions. SEM, TEM and XRD characterization show that the amorphous Co–P/NF electrocatalysts have rough surface structures, exposing more active sites for oxygen evolution reaction. The electrochemical measurements confirm that Co–P alloys have excellent activity for oxygen evolution reaction, with an overpotential of 306 mV (at j = 10 mA cm−2), a lower Tafel slope of 51.1 mV dec−1 and long-term stability (>25 h) under alkaline conditions (1.0 M KOH). Image 101 • The Co–P/NF electrocatalysts are prepared by electroless deposition technology only need 10 min under mild conditions. • The change of Co–P/NF electrocatalysts after the stability test is carefully studied. • The OER activity can be maximumly promoted and maintained for Co–P/NF catalyst. • This work provides an important platform for further industrial production. [ABSTRACT FROM AUTHOR]