Template-free synthesis of 1D hollow Fe doped CoP nanoneedles as highly activity electrocatalysts for overall water splitting

Development of low cost and high efficiency electrocatalysts for water splitting systems to produce renewable hydrogen energy is still a significant requirement. The engineering of nanostructure and element doping are effective methods to further improve the performance of catalysts. Nonmetal (such as N, P, S) doping has been extensively investigated, while the report of metal doping is relatively few. Herein, Fe doped CoP 1D hollow nanoneedles on carbon cloth (CC) are designed and fabricated by a hydrothermal method and subsequent phosphorization procedure. The conversion of Fe doped Co-hydroxide@CC to Fe–CoP can produce large number of nanopores, which are closely connected to each other, and form hollow structures within the nanoneedles. Benefiting from the effective Fe doping and the particular hollow nanoneedle structure, the obtained Fe–CoP@CC demonstrates good electrocatalytic activity for hydrogen evolution reaction (HER) both in alkaline and acidic solution, affording a current density of 10 mA cm⁻² at overpotential of 49 mV and 80 mV, respectively. Moreover, the two-electrode electrolyzer with Fe–CoP@CC as both the cathode and anode catalyst achieve a current density of 10 mA cm⁻² at a cell voltage of 1.58 V in 1.0 M KOH solution. The results illustrate that the obtained hollow Fe–CoP@CC nanoneedles can serve as an efficient catalyst for overall water splitting.     

Proton-conducting barium stannates: Doping strategies and transport properties

High temperature proton conductors (HTPCs) find their applications in steam electrolysis, gas sensing, and most importantly, fuel cells. In this work, proton conductivities and transport properties of doped BaSnO₃ are investigated. Samples of BaSn_0.9D_0.1O_2.95 (D = In, Lu, Er, Y, and Gd) were prepared by solid-state reaction and relative densities >93% were achieved after sintering at 1600 °C or lower. Although Y doping is commonly known to yield the highest conductivities for BaCeO₃ and BaZrO₃, In-doped BaSnO₃ exhibits the highest conductivity and conductivities decrease in the order In > Lu > Er > Y > Gd. Ionic radius and electronegativity matching between dopants and host Sn⁴⁺ is shown to be an important doping strategy for enhancing conductivities of BaSnO₃. Measurements of H/D isotope effect and electromotive force (EMF) were performed on BaSnO₃ to give direct evidence for proton conduction and to examine transport properties. The ratio between conductivities in H- and D-atmosphere (σ_H/σ_D) is 2.62 in reducing conditions, indicating protons transfer via the Grötthus mechanism. Proton transport numbers reached above 0.75 at 450 °C, and n- and p-type electronic conduction is identified to be secondary in reducing and oxidizing atmospheres, respectively. Electronic contribution to conductivity is found to increase with temperatures. Conductivities of BaSnO₃ are seen to be comparable to Y-doped BaZrO₃ (e.g., grain conductivities for both Y-doped BaSnO₃ and BaZrO₃ are ∼1.5 × 10⁻⁴ S cm⁻¹ at 350 °C), and are much higher than other common HTPCs, such as LaPO₄ and LaNbO₄. The high conductivity and good sinterability make BaSnO₃ a promising HTPC.     

Engineering hollow Ni–Fe-based mesoporous spherical structure derived from MOF for efficient photocatalytic hydrogen evolution

Endowing photocatalyst with functional nanostructure can effectively improve its performance towards solar energy conversion. Here, a unique Ni–Fe-based mesoporous hollow spherical nanostructure (NiFeOx/NC-t) was facilely constructed via the direct thermal decomposition of Ni-BTC@PBA composites. The hybrids consist of in-situ formed nitrogen-enriched carbon layers constituting the mesoporous walls of hollow spherical, and amorphous NiFeO_x nanoparticles and a small fraction of FeNi₃ are embedded on the spherical walls during carbonization. After loading EY molecules on NiFeOx/NC-t as solar light absorbers, an optimal photocatalytic hydrogen evolution rate of 5352.7 μmol g^?1 h^?1 was achieved with excellent stability under visible light (λ > 420 nm) in the absence of co-catalyst. The excellent photocatalytic activity was revealed to be ascribed to: ⅰ) mesoporous hollow spherical structure having a large surface area, thus exposing more active sites; ⅱ) efficient injection of photo-generated electrons from excited EY^? into NiFeO_x and FeNi₃ by the bridge of high-conductive nitrogen-enriched carbon layer. In brief, the structural and compositional features synergistically strengthen the photocatalytic activity of NiFeOx/NC-t. It is worth noting that MOF-derived route can significantly simplify the preparation process of mesoporous hollow spherical nanostructure. This work provides an approach for facile preparation of versatile photocatalysts with high efficiency for solar energy conversion.     

The effect of powder preparation method on the artificial photosynthesis activities of neodymium doped titania powders

The effects of nanostructure on the artificial photosynthesis activities of undoped and Nd doped titania (TiO₂) powders prepared by three different chemical co-precipitation methods were investigated. Substitutional/interstitial N and S doping was observed in powders due to the presence of high concentrations of HNO₃ (NP) and H₂SO₄ (SP) in the powder preparation media, respectively. Nd, N and S doping caused anatase/rutile phase transformation inhibition and crystallite size reduction in the nanostructure. Light absorption was significantly enhanced by Nd doping and the residual SO₄^2?/NO_x species in the nanostructure. Photocatalytic hydrogen production activity of Nd doped NP powder was 4 times greater than undoped NP powder at 700 °C and had a high purity (CO:H₂ ratio～0.00). CO was determined to be the main product in photocatalytic CO₂ reduction. NP powders had the highest CO yields and Nd doping enhanced CO production. The powders with high crystallite sizes and rutile weight fractions had the highest artificial photosynthesis activities.     

Hollow NH2-MIL-101@TA derived electrocatalyst for enhanced oxygen reduction reaction and oxygen evolution reaction

Non-precious metal-based electrocatalysts with excellent activity and stability are highly desired for the sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, a tannic acid (TA) etching strategy is used to inhibit the metal aggregation and achieve muti-metal doping. The hollow NH₂-MIL-101@TA derived Fe–N–C catalyst exhibits superior ORR catalytic activity with an E_1/2 of 0.872 V and a maximum output power density of 123.4 mW cm⁻² in Zn-air battery. Since TA can easily chelate with metal ions, Fe/Co–N–C and Fe/Ni–N–C are also synthesized. Fe/Ni–N–C manifests exceptional bifunctional activity with an E_j = 10 of 1.67 V and a potential gap of 0.833 V between E_j = 10 and E_1/2 in alkaline electrolyte, which is 45 mV smaller than Pt/C–IrO₂. The improvement of ORR and OER performance of the catalysts via the simple TA etching and chelation method provides a novel strategy for the design and synthesis of efficient electrocatalysts.     

Construction of hollow structure cobalt iron selenide polyhedrons for efficient hydrogen evolution reaction

The development of highly active, robust and cost-effective noble metal-free electrocatalysts for hydrogen evolution reaction (HER) in alkaline solution remains a severe challenge. In this work, a hollow structure CoSe₂-FeSe₂ heterojunction electrocatalyst (denoted by “(Co,Fe)Se₂”) was designed by a simple anion exchange reaction and selenization. Benefiting from the unique hollow structure, the (Co,Fe)Se₂ catalyst accelerates diffusion of electrolyte, besides, the CoSe₂-FeSe₂ heterojunction could provide rapid interfacial charge transportation and more active sites for the HER reaction. The (Co,Fe)Se₂ electrode material exhibits good performance for HER in 1 M KOH electrolyte. It needs an overpotential of 124 mV to obtain a current density of 10 mA cm⁻², and the Tafel slope is 65 mV dec⁻¹. Besides, (Co,Fe)Se₂ has a smaller charge transfer resistance compared with CoSe₂. At the same time, it has relatively large electrochemical active surface area due to the porosity. Most importantly, the (Co,Fe)Se₂ electrode displays good stability in alkaline conditions for 15 hours, the linear sweep voltammetry curves are almost coincident before and after 1000 cycles, the overpotential with current density of 10 mA cm⁻² increased by only 9.76% after 5000 cycles of CV. It shows great application potential in HER.     

PtFe and Fe3C nanoparticles encapsulated in Fe–N-doped carbon bowl toward the oxygen reduction reaction

The high-temperature calcination strategy facilitates the formation of alloy atoms but inevitably results in the aggregation and deactivation of the metal particles for the oxygen reduction reaction (ORR) electrocatalysts. Herein, we report the successful encapsulation of Platinum–Iron (PtFe) nanoparticles (∼4.7 nm) in the N-doped hollow carbon hemisphere matrix (NCB) containing Fe–N and Fe₃C without employing high-temperature pyrolysis, which effectively facilitates the well-dispersed Pt nanoparticles and the formation of PtFe nanoalloys. The hollow carbon hemisphere structure contributes to the expansion of the specific surface area and exposure of active sites of the catalyst, meanwhile, the modification of the surface of the carbon nano-bowl from a predominantly Fe to a functional electrocatalyst with a primarily PtFe alloy can boost the ORR catalytic activity and stability. It is found that the Pt3Fe/Fe₃C-NCB catalyst exhibits the optimum ORR performance with a mass activity (0.97 A mg⁻¹_Pt), 5.10 times higher than the commercial Pt/C (0.19 A mg⁻¹_Pt). Pt3Fe/Fe₃C-NCB also displays excellent durability in comparison to the commercial Pt/C after 20,000 potential cycles. Combined with the Physical characterization and the electrochemical test results, Fe₃C-NCB plays a strong metal-support role for the encapsulated PtFe nanoparticles structure, thereby preventing nanoparticle migration and corrosion. Experimental characterization and theoretical calculations show that the appropriate PtFe alloy composition and the strain effect induced by Fe–N/Fe₃C active sites are sufficient to accelerate the detachment of oxygenated species from the alloy surface, resulting in a catalyst with excellent ORR performance.     

High-performance bifunctional Fe-doped molybdenum oxide-based electrocatalysts with in situ grown epitaxial heterojunctions for overall water splitting

The design and development of low-cost, abundant reserves, high catalytic activity and durability bifunctional electrocatalysts for water splitting are of great significance. Here, simple hydrothermal and hydrogen reduction methods were used to fabricate a uniform distribution of Fe-doped MoO₂/MoO₃ sheets with abundant oxygen vacancies and heterojunctions on etched nickel foam (ENF). The Fe– MoO₂/MoO₃/ENF exhibited a small overpotential of 36 mV at 10 mA cm⁻² for hydrogen evolution reaction (HER), an excellent oxygen evolution reaction (OER) overpotential of 310 mV at 100 mA cm⁻² and outstanding stabilities of 95 h and 120 h for the HER and OER, respectively. As both cathode and anode catalysts, the heterogeneously structured Fe– MoO₂/MoO₃/ENF required a low cell voltage of 1.57 V at 10 mA cm⁻². Density functional theory (DFT) calculations show that Fe doping and MoO₂/MoO₃ heterojunctions can significantly reduce the band gap of the electrode, accelerate electron transport and reduce the potential barrier for water splitting. This work provides a new approach for designing metal ion doping and heterostructure formation that may be adapted to transition metal oxides for water splitting.     

Phosphorus-doping induced electronic modulation of CoS2–MoS2 hollow spheres on MoO2 film-Mo foil for synergistically boosting alkaline hydrogen evolution reaction

Combination of anionic doping and multicomponent synergism are effective approach to improve the performance of electrocatalysts toward hydrogen evolution reaction (HER) process. Herein, P-doped CoS₂–MoS₂ hollow spheres assembled by countless sheets on oxidized Mo foil (P–CoS₂/MoS₂/MoO₂) was synthesized by hydrothermal and phosphorization process. The unique hollow structure with countless sheets as wall endows more accessible active sites, fast electron/mass transport and high conductivity. P-doping could redistribute the local charge density and optimize the surface charge state to improve the intrinsic activity and accelerate reaction kinetics. The optimized P–CoS₂/MoS₂/MoO₂ exhibits an outstanding HER performance with an overpotential of 85 mV to reach 10 mA cm⁻², a small Tafel slope of 84.6 mV dec⁻¹, superior intrinsic HER activity and robust durability under alkaline solution. This work proposed a feasible strategy to build the hollow, heterostructured and binder-free electrode in renewable energy application.     

Okra-like hollow Cu0.15-CoP/Co3O4@CC nanotube arrays catalyst for overall water splitting

The manufacture of hydrogen energy by overall water splitting (OWS) has been broadly considered as a promising candidate for constant energy systems. Herein, we report an okra-like hollow Cu_0.15-CoP/Co₃O₄@CC nanotube arrays catalyst through a simple hydrothermal-phosphating method. As a noble-metal-free catalyst, it exhibits outstanding HER (hydrogen evolution reaction) catalytic activity with an overpotential of 13 mV to achieve 10 mA cm^?2 in 1 M KOH electrolyte. For OER (oxygen evolution reaction), it demands 225 mV to achieve 10 mA cm^?2. When okra-like hollow Cu_0.15-CoP/Co₃O₄@CC is used as both cathode and anode electrode materials, 1.487 V is required to reach 10 mA cm^?2 for OWS, better than numerous electrocatalysts that have been reported. Moreover, it displays excellent stability in a continuously 60 h i-t test, proving an enormous potential for large-scale applications. The theoretical calculation of density functional theory (DFT) further reveals that Cu doping can bring localized structure polarization and reduce the hydrogen adsorption free energy (ΔG_H1) on the interstitial sites, thus leading to a significant increase in catalytic activity.     

Interface engineering of the NiCo2O4@MoS2/TM heterostructure to realize the efficient alkaline oxygen evolution reaction

Electrochemical water splitting is considered as a promising strategy for the efficient hydrogen production, yet it is hindered by the sluggish oxygen evolution reaction (OER). Herein, heterostructure OER catalyst is fabricated by combining MoS₂ nanosheets with NiCo₂O₄ hollow sphere on Ti mesh. Benefiting from the heterogeneous nanointerface between NiCo₂O₄ and MoS₂, this electrocatalyst demonstrates excellent OER activity in basic environment with overpotentials of 313 and 380 mV achieving 10 and 100 mA cm⁻². The superb catalytic performance stems from hollow the nanostructure and interfacial engineering strategy that enhance intrinsic activity and provide faster charge transfer. Hence, this work provides a feasible path for exploiting the high-efficient catalysts.     

Hollow bimetallic M-Fe-P (M=Mn,Co, Cu) nanoparticles as efficient electrocatalysts for hydrogen evolution reaction

Searching for low-cost electrocatalysts with high activity towards the hydrogen evolution reaction (HER) is of great significance to enable large-scale hydrogen production via water electrolysis. In this study, by using inverse spinel MFe₂O₄(M = Mn, Fe, Co, Cu) nanoparticles (NPs) as the precursors, monodisperse bimetallic phosphide M-Fe-P NPs/C with hollow structures were readily obtained by a gas-solid annealing method. These hollow phosphide NPs displayed excellent HER activity in an acidic medium with a low loading amount of 0.2 mg cm⁻². In particular, the Co–Fe–P NPs/C shows highest HER activity that only requiring an overpotential of 97 mV to retain a current density of 10 mA cm⁻². A volcano relation between activity and incorporated elements was revealed. Incorporation of cation with high electronegativity stabilized the FeP active centres, while phase segregation resulted in the loss of activity for Cu–Fe–P NPs/C.     

Alloyed palladium-nickel hollow nanospheres with interatomic charge polarization for improved hydrolytic dehydrogenation of ammonia borane

Hydrolysis reaction of ammonia borane (AB) has been considered as a safe and efficient hydrogen generation method, in which designing cost-effective and high-performance catalysts plays vital role. In this work, we have developed well dispersed palladium-nickel hollow nanospheres (PdNi HNSs) with tunable shell thickness and compositions via a facile galvanic replacement approach. The as-prepared PdNi HNSs show composition-dependent catalysis in the hydrolytic dehydrogenation of AB. The Pd₈₄Ni₁₆/C exhibiting sphere-shaped hollow interiors with average 70 nm particle size and 10 nm thin wall, presents the highest catalytic activity with the turnover frequency of 76.0 (mol H₂ min^?1 (mol Pd)^?1) and the activation energy of 33.5 kJ mol^?1. The superior catalytic effect of PdNi HNSs in enhancing hydrolysis efficiency of AB can be ascribed to two major factors: (1) high active surface areas of the unique hollow structure; (2) enhanced H adsorption attributed to the coupling between Pd and Ni induces polarization charges on Pd catalytic sites, which is indicated by the first-principles calculation and X-ray photoelectron spectroscopy studies. Furthermore, the catalysts exert good long-term recycling stability and catalytic activity for the hydrolytic dehydrogenation of AB. This work represents a strategy may hopefully be extended to synthesize other Pd-based hollow nanostructure with reduced Pd usage and increased catalytic active sites, and also sheds light on the exploration of utilizing interatomic interactions to regulate species adsorption/activation for highly efficient catalytic performance.     

Green solid-state fabrication of new nanocomposites based on La–Fe–O nanostructures for electrochemical hydrogen storage application

Nano-sized La–Fe–O (LFO) structures were fabricated via novel free-solvent and green solid-state route using La (acac)₃. H₂O and Fe (acac)₃ complex precursors. Acetylacetonate (acac) in organometallic complex precursors control nucleation and growth of formed crystals with creation spatial barrier around the cations, and prevent nano-product agglomeration. The mechanism of role of acac has been explained in nanostructure formation. Changing of parameters in synthesis reaction consisting La:Fe molar ratio, calcination time and temperature in turn offer a virtuous control over the nanocomposites size and shape which various compositions of La₂O₃/LaFeO₃, LaFeO₃/La₂O₃ and LaFeO₃/Fe₂O₃ obtained. The as-prepared La–Fe–O nano-products were characterized thorough Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR), UV–Vis, BET and energy dispersive X-ray (EDX) analysis in terms of crystallinity structure, composition, porosity and morphology. Different formed La–Fe–O nanostructures were evaluated for electrochemical hydrogen storage capacity through chronopotentiometry technique in stable current (1 mA). The achieved La–Fe–O nanoparticles could be applied as a favorable candidate active material for electrochemical hydrogen storage. Optical, magnetic and reducible characteristics of La–Fe–O nanostructures have positive effect on electrochemical hydrogen storage capacity. It was found out that the LaFeO₃/Fe₂O₃ nanocomposites have the best electrochemical hydrogen storage performance due to oxidation-reduction process of Fe²⁺/Fe³⁺ components which can help to charge-discharge process of hydrogen to increase the storage capability to 790 mAhg^?1 after 20 cycles. Also, the mixed metal oxides illustrate advanced discharge capacity than other binary oxides.     

BaCe0.85Tb0.05Co0.1O3−δ perovskite hollow fibre membranes for hydrogen/oxygen permeation

Co-doped BaCe_0.85Tb_0.05Co_0.1O_3−δ (BCTCo) nanopowder was synthesized via a sol–gel method using ethylenediaminetetraacetic acid (EDTA) and citric acid as the chelating agents. Using the resultant powder, BCTCo perovskite hollow fibre membranes were then fabricated by the combined phase inversion and sintering technique. Properties of the BCTCo powder and the hollow fibre membranes in terms of crystalline phase, morphology, electrical conductivity, porosity, mechanical strength and hydrogen/oxygen permeation were investigated by a variety of characterization methods. The results indicated that doping of cobalt in the BCTb oxide led to a higher electrical conductivity and lower calcination temperature for the powder precursor to a perovskite structure as well as sintering temperature for the hollow fibre precursors to gastight membranes. In order to obtain gastight and robust hollow fibre membranes, the sintering temperature should be controlled between 1300 and 1450 °C. The maximum hydrogen flux through the BCTCo hollow fibre membranes reached up to 0.385 mL cm⁻² min⁻¹ at 1000 °C under 50% H₂–He/N₂ gradient, which is higher than that of the un-doped BCTb hollow fibre membranes with the same effective thickness, and especially much higher than that obtained from other proton conductors due to the asymmetric structure of the membrane designed. Moreover, the BCTCo hollow fibre membrane also exhibited noticeable oxygen permeation fluxes, i.e. 0.122 mL cm⁻² min⁻¹ at 1000 °C under the air/He gradient. However, doping of cobalt might damage the mechanical stability of the perovskite membranes in the hydrogen-containing atmosphere.     

The ZnIn2S4/CdS hollow core-shell nanoheterostructure towards enhanced visible light photocatalytic H2 evolution via bimetallic synergism

The ZnIn₂S₄/CdS hollow core-shell nanoheterostructure with bimetallic synergism is synthesized via a hybrid chemical method. As revealed, the ZnIn₂S₄/CdS hollow core-shell nanoheterostructure (ZnIn₂S₄/CdS-3) exhibits remarkable visible light photocatalytic hydrogen evolution (～5209.43 μmol·g^?1·h^?1, AQE of ～20.26%) than that of single CdS (～40 folds) and single ZnIn₂S₄ (～12 folds), and achieves decent photocatalytic stability (average HER performance of ～5056.80 μmol·g^?1·h^?1), which is mainly ascribed to that, the formed ZnIn₂S₄/CdS heterostructure with appropriate potential gradient and Zn/In bimetallic synergism can improve carrier transportation, including increasing carrier transportation, prolonging lifetime and decreasing recombination, the hollow core-shell nanostructure can provide abundant active sites and increase solar efficiency, while can maintain a photocatalytic stability.     

CNT-interconnected iron-doped NiP2/Ni2P heterostructural nanoflowers as high-efficiency electrocatalyst for oxygen evolution reaction

Oxygen evolution reaction (OER) plays a decisive role in electrolytic water splitting. However, it is still challengeable to develop low-cost and efficient OER electrocatalysts. Herein, we present a combination strategy via heteroatom doping, hetero-interface engineering and introducing conductive skeleton to synthesize a hybrid OER catalyst of CNT-interconnected iron-doped NiP₂/Ni₂P (Fe-(NiP₂/Ni₂P)@CNT) heterostructural nanoflowers by a simple hydrothermal reaction and subsequent phosphorization process. The optimized Fe-(NiP₂/Ni₂P)@CNT catalyst delivers an ultralow Tafel slope of 46.1 mV dec^?1 and overpotential of 254 mV to obtain 10 mA cm^?2, which are even better than those of commercial OER catalyst RuO₂. The excellent OER performance is mainly attributed to its unique nanoarchitecture and the synergistic effects: the nanoflowers constructed by a 2D-like nanosheets guarantee large specific area and abundant active sites; the highly conductive CNT skeleton and the electronic modulation by the heterostructural NiP₂/Ni₂P interface and the hetero-atom doping can improve the catalytic activity; porous nanostructure benefits electrolyte penetration and gas release; most importantly, the rough surface and rich defects caused by phosphorization process can further enhance the OER performance. This work provides a deep insight to boost catalytic performance by heteroatom doping and interface engineering for water splitting.     

Graphene nanosheet–CNT hybrid nanostructure electrode for a proton exchange membrane fuel cell

This work demonstrates two-step growth of graphene nanosheets (GNS), in which carbon nanotubes (CNTs) are grown directly on a carbon cloth. GNS are subsequently constructed on the CNT surface, revealing the stand-up structure of the GNS–CNT hybrid nanostructure. The GNS–CNT hybrid nanostructure shows Nernstian and fast electron-transfer kinetics for electrochemical reactions of Fe(CN)₆^3−/4−. A 0.1 mg cm⁻² Pt/GNS–CNT is used in the cathode of a proton membrane exchange fuel cell, in which the maximum power density is 1072 mW cm⁻² at 80 °C under H₂/O₂. In addition to a low-resistance electron-transfer pathway, the GNS–CNT hybrid nanostructure also provides numerous edge planes with strong electrochemical activity, ultimately enhancing electrochemical activity and fuel cell performance.     

Effects of the cation and anion co-doping in perovskite as bifunctional electrocatalyst for water splitting

Element doping is a very important way to modify perovskite oxide (ABO₃) electrocatalyst. Herein, the O, B and A-site of BaCoO_3-δ are doped with F, Fe and Sr elements, respectively, which are used to investigate the effect of different doping sites on water splitting performance. The results show that doping F can generate more oxygen vacancies and increase the Co valence state. On the basis of anionic doping, when Co is partially substitute by Fe, the Fe⁴⁺ formed makes the O 2P orbital close to E_F, and the bandwidth is narrower, enhancing the conductivity. Subsequently, doping Sr in A-site can change the crystal structure from P63/mmc to pm-3m, and exhibit metallic properties. This work can contribute to an effective approach for the design of perovskite oxide materials for efficient electrocatalytic water splitting.     

Template assisted hydrothermal synthesis of CoSnO3 hollow microspheres for electrocatalytic oxygen evolution reaction

The practical complications suffered by the most recognized electrochemical energy systems, such as, water-electrolyzers and metal-air batteries reside in the half-cell oxygen evolution reaction. To resolve this problem, continuous colossal efforts are required to develop the active, affordable and sustainable electrocatalysts. Shape-tailoring of the catalysts, constructed from non-noble metals is one of the emerging strategies to augment the activity of the material toward electrochemical reactions. In the present work, we demonstrate the template-assisted hydrothermal synthesis of hierarchical CoSnO₃ hollow microspheres, constructible from the wafer-thin sheets of CoSnO₃. The hierarchical CoSnO₃ hollow microspheres possess a high specific surface area of 153.59 m²/g, and mesoporous configuration, which are the essential pre-requisites of an electrochemical system. In addition to this, the proposed CoSnO₃ hollow microspheres possess adequate electroactive surface area (793.5 cm²) and happens to be a suitable candidate for driving the oxygen evolution reaction with a low overpotential of 282 mV and Tafel slope of 96.5 mV/dec in alkaline medium. The higher turnover frequency (0.0045 s⁻¹), high specific and mass activities (2.195 mA/cm²_EASA and 28.752 mA/mg, respectively) were observed for CoSnO₃ hollow spheres. Furthermore, the chronoamperometric measurement reveals a good stability of CoSnO₃ hollow microspheres in alkaline condition, satisfying the fundamental demand of an energy system.