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[Display omitted] Oxygen evolution reaction (OER) process is the "bottleneck" of water splitting, and the low-cost and high-efficient OER catalysts are of great importance and attractive but they are still challenging. Herein, a dual modification strategy is developed to tune and enrich the structure of cobalt silicate (Co 2 SiO 4) showing boosted OER properties. Cobalt oxide (Co 3 O 4) decorated Co 2 SiO 4 nanobelts, denoted as CS, is firstly prepared using a Co-based precursor by a facile hydrothermal reaction. Then, cobalt phosphide (CoP) nanoparticles are in-situ grown on CS (denoted as CS-P) by the phosphorization process, which provide many active sites and boost the surface reactivity. The experimental results and density function theory (DFT) calculations both reveal that the CoP on CS can improve the conductivity and ensure fast kinetics, thus leading to boost the OER properties of Co 2 SiO 4. When the phosphorization temperature is at 400 °C (CS-P400), it gains the lowest overpotential of 297 mV, which is much lower than CS (340 mV) and Co 2 SiO 4 (409 mV) at 10 mA·cm−2, and even superior to the state-of-the-art transition metal silicates. CS-P400 also achieves high electrochemical active surface area (ECSA) and small Tafel slope owing to its porous structures with large specific surface area and nanosheet-like structures which are good for exposing many active sites and favorable to the fast kinetics. This work not only provides a dual modification route to boost catalytic activity of Co 2 SiO 4 (CS-P400), but also sheds light on a new avenue for developing highly dispersed CoP on silicates to boost OER performances. [ABSTRACT FROM AUTHOR]

Developing effective and long-lasting electrocatalysts for oxygen evolution reaction (OER) is critical for increasing sustainable hydrogen production. This paper describes the production and characterization of CoFeP nanoparticles (CFP NPs) as high-performance electrocatalysts for OER. The CFP NPs were produced using a simple hydrothermal technique followed by phosphorization, yielding an amorphous/crystalline composite structure with improved electrochemical characteristics. Our results reveal that CFP NPs have a surprisingly low overpotential of 284 mV at a current density of 100 mA cm−2, greatly exceeding the precursor CoFe oxide/hydroxide (CFO NPs) and the commercial RuO2 catalyst. Furthermore, CFP NPs demonstrate exceptional stability, retaining a constant performance after 70 h of continuous operation. Post-OER characterization analysis revealed transformations in the catalyst, including the formation of cobalt–iron oxides/oxyhydroxides. Despite these changes, CFP NPs showed superior long-term stability compared to native metal oxides/oxyhydroxides, likely due to enhanced surface roughness and increased active sites. This study proposes a viable strategy for designing low-cost, non-precious metal-based OER catalysts, which will help advance sustainable energy technology. [ABSTRACT FROM AUTHOR]

[Display omitted] Oxygen Evolution Reaction (OER) has gained significant attention due to its crucial role in renewable energy systems. The quest for efficient and low-cost OER catalysts remains a challenge of significant interest and importance. In this work, phosphate-incorporated cobalt silicate hydroxide (denoted as CoSi-P) is reported as a potential electrocatalyst for OER. The researchers first synthesized hollow spheres of cobalt silicate hydroxide Co 3 (Si 2 O 5) 2 (OH) 2 (denoted as CoSi) using SiO 2 spheres as a template through a facile hydrothermal method. Phosphate (PO 4 3−) was then introduced to layered CoSi, leading to the reconstruction of the hollow spheres into sheet-like architectures. As expected, the resulting CoSi-P electrocatalyst demonstrated low overpotential (309 mV at 10 mA·cm−2), large electrochemical active surface area (ECSA), and low Tafel slope. These parameters outperform CoSi hollow spheres and cobaltous phosphate (denoted as CoPO). Moreover, the catalytic performance achieved at 10 mA cm−2 is comparable or even better than that of most transition metal silicates/oxides/hydroxides. The findings indicate that the incorporation of phosphate into the structure of CoSi can enhance its OER performance. This study not only provides a non-noble metal catalyst CoSi-P but also demonstrates that the incorporation of phosphates into transition metal silicates (TMSs) offers a promising strategy for the design of robust, high-efficiency, and low-cost OER catalysts. [ABSTRACT FROM AUTHOR]

Developing cost-effectiveness and superior electrocatalysts is crucial to improve the efficiency of oxygen evolution reaction (OER) in water splitting system. Hence, flower-like phosphorus doped Ni 3 S 2 /CoFe 2 O 4 arrays (P-Ni 3 S 2 /CoFe 2 O 4 /NF) were generated on three-dimensional (3D) nickel foam (NF) via the two-step hydrothermal treatment and subsequent phosphorization. Additionally, a series of control experiments were conducted to investigate the formation mechanism. By virtue of the unique 3D configurations and multi-compositions, the as-prepared catalyst exhibited greatly improved OER performance in 1.0 M KOH solution, with the overpotential of only 254 mV at 50 mA cm−2 and low Tafel slope of 54.43 mV dec−1. This study provides a feasible approach for preparing advanced electrocatalyst in energy conversion and storage devices. [ABSTRACT FROM AUTHOR]

To solve energy‐related environmental problems and the energy crisis, efficient electrochemical materials have been developed as alternative energy storage and conversion systems. Abundant transition metals and their sulfides are attractive electrochemical materials. Herein, we report an efficient phosphorization strategy, which improves the overall electrochemical performance of metal sulfides. In detail, CoS hexagonal bipyramids were synthesized through simple calcination combined with in situ sulfurization of a cobalt‐based metal–organic framework template, and then phosphate ion‐functionalized CoS (P‐CoS) was prepared through a phosphorization reaction. P‐CoS exhibited outstanding electrochemical activity as both supercapacitor electrode and oxygen evolution reaction (OER) catalyst. Supercapacitors based on CoS and P‐CoS as the electrodes had high specific capacitances of 304 and 442 F g−1, respectively, and remained stable for over 10 000 cycles at 5 A g−1. For OER, P‐CoS showed a current density of 10 mA cm−2 at an overpotential of 340 mV, with a small Tafel slope. In conclusion, functionalizing CoS with phosphate ions is a promising method for enhancing chemical reactivity and accelerating ion and electron transfer. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract Exploring low-cost and outstanding bimetallic phosphides to substitute noble metals as electrocatalysts for oxygen evolution reaction (OER) in alkaline media is essential for renewable energy technologies. Herein, bimetallic nickel-iron phosphides nanoparticles (P-NiFe-800 NPs) with rich defects have been synthesized through gas annealing at 800 °C and phosphorization using uniform nickel-iron nanocubes (NiFe NCs) as precursor. At optimized calcination temperature, the obtained P-NiFe-800 NPs are composed of uniform nanoparticles with the rough surface, which suggests the larger surface area and more exposed rich active sites than other samples for OER. The introduction of P element to binary nickel-iron metals can optimize the crystalline and electronic structures of NiFe NCs and thus enhance electrocatalytic properties. Owing to the distinct morphological structure and synergistic effect between nickel-iron and phosphorus, P-NiFe-800 NPs demonstrate superior electrocatalytic activities for OER with lower overpotential of 270.1 mV to achieve a current density of 10 mA cm−2, smaller Tafel slope of 39 mV dec−1, lower electrochemical impedance spectroscopy (EIS) value, bigger determined double-layer capacitance (C dl) of 2130 uF cm−2 and prominent stability than NiFe NCs, NiFe-600 NPs, NiFe-700 NPs, NiFe-800 NPs, NiFe-900 NPs, P-NiFe NCs, P-NiFe-600 NPs, P-NiFe-700 NPs and P-NiFe-900 NPs. The optimized phosphorization is helpful for fabricating the bimetallic phosphides as efficient catalysts for OER. [ABSTRACT FROM AUTHOR]

The metal-organic frameworks (MOFs)/derivates emerged as promising catalysts for hydrogen generation from electrolyzing water, however, further improvements in the activities are still awaited. Herein, bimetallic MOFs and the derivates were developed for catalyzing the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) by regulating the morphology, and activity of the intermediates. We demonstrated the activity and morphology of the catalysts strongly correlated with the atomic ratio of Ni and Co in bimetallic MOFs. The hierarchical Ni 0.1 Co 0.9 -MOF delivered a relatively low overpotential of 384 mV to afford 100 mA/cm2 for OER, but a high overpotential of 512 mV for HER. While the phosphide Ni 0.1 Co 0.9 P only needed an overpotential of 276 mV to deliver 100 mA/cm2 for HER. And we discussed the roles of bimetallic sites and phosphorous in OER and HER in depth. More importantly the Ni 0.1 Co 0.9 -MOF and Ni 0.1 Co 0.9 P were integrated to drive the overall water splitting, at a current density of 10 mA/cm2, the overpotential value is 500 mV. This work provided insights into the exploration of efficient MOFs/derivates catalysts and shed new light on the novel combination for water electrolysis. [Display omitted] • The hierarchical nanoflower morphology is elaborately fabricated. • The OER activity highly depends on the metallic atomic ratio in NiCo-MOF. • Ni 0.1 Co 0.9 -MOF performs the most superior OER performance. • Boosted HER performance is achieved by phosphorization (Ni 0.1 Co 0.9 P). • Paring Ni 0.1 Co 0.9 -MOF and Ni 0.1 Co 0.9 P generate excellent water electrolysis. [ABSTRACT FROM AUTHOR]

Oxygen evolution reaction (OER) is a vital process in numerous energy conversion systems, and therefore, considerable attention has been devoted to the fabrication of nonnoble and highly efficient electrode materials for OER. Herein, Co nanoparticles embedded in the N, P-codoped porous carbon (Co/P-N-C) are synthesized using a novel Co-based metal-organic polymer (Co-MOP) as the precursor through carbonization and a subsequent phosphorization treatment process. When the phosphorization treatment is carried out at pH 3, Co/P-N-C exhibits a very low overpotential of 300 mV for a current density of 10 mA cm−2 with a small Tafel slope of 61 mV dec−1 and excellent stability over 20000 s. The electrocatalytic performance of Co/P-N-C was even better than that of the commercial RuO 2 material. Density functional theory calculations were used to simulate the electrocatalytic process and to verify the experimental findings, which showed that the superior OER performance was attributed to the active sites of doped P and Co nanoparticles. This viable strategy of using a novel Co-MOP to create a novel phosphorized Co/P-N-C microporous carbon-based material may expand the opportunities for the exploration of high-performance and robust nonnoble metal electrocatalysts for energy-conversion reactions. Co atoms on N, P co-doped porous carbon via phosphorization on Co-MOP exhibit excellent OER performance due to the synergistic effects of P and Co. Image 1 • A phosphorization strategy to prepare a porous MOP-derived Co-P-N-C nanosphere. • The as-obtained yolk-shell Co-P-N-C nanosphere possesses the high electrocatalytic activity for OER. • Reveal the P and Co synergistic mechanism for forming more active sites of Co-P-N-C. [ABSTRACT FROM AUTHOR]