Evolution Activity Research Articles

Synthesis of O,F Co-Modified g-C3N4 for Photocatalytic H2 Evolution Activity Improvement and Corrosion Protection

Herein, we report the rational synthesis of porous g-C3N4 co-modified with oxygen (O) and fluorine (F) for the first time. Incorporating colloidal SiO2 during thermal polymerization introduces lattice oxygen, forming C–O bonds, while post-treatment with NH4·HF2 establishes C–F bonds. The dual incorporation of O and F elements extends visible light absorption and effectively promotes the separation and transport of photoexcited charge carriers. Consequently, the co-modified g-C3N4 (O,F-g-C3N4) achieves a 13.2-fold increase in H2 evolution rate compared to pristine g-C3N4. This synthesized O,F-g-C3N4 is then dispersed in waterborne polyurethane (WPU) to create an anti-corrosive coating for Q235 carbon steel substrates. Water resistance, mechanical property, and electrochemical characterization analyses reveal that the O,F-g-C3N4/WPU composite coating exhibits remarkable corrosion resistance with a high protection efficiency of 90.23%. This work offers a straightforward approach for developing highly efficient g-C3N4-based photocatalysts and corrosion-resistant coatings.

Electrode Selection and Catalyst Evaluation in Hydrogen Production from Alkaline Water Electrolysis: A Review

Generating hydrogen, through alkaline water electrolysis shows promise as an energy source. This review delves into the significance of choosing the electrodes and evaluating catalysts to enhance the efficiency and performance of hydrogen production. It summarizes the activation energy and losses linked to reactions in alkaline electrolysis emphasizing the necessity for electrode materials and catalysts. The review also touches upon challenges such as electricity consumption and platinum group metal based electro catalysts proposing various electrode materials and catalysts with superior activity and selectivity for hydrogen production. Additionally, it discusses electrolysis cell designs that facilitate separating by-products from hydrogen gas. The study reveals that with low over potentials of 70, 318, and 361 mV at 10, 500, and 1000 mA cm−2, respectively, NiOx/NF exhibits strong alkaline hydrogen evolution activity, resulting in great performance in alkaline HER. Moreover, it outlines advancements in alkaline water electrolysis technology focusing on enhanced efficiency and reduced operating costs associated with electricity consumption. Overall this review underscores the role of selecting electrodes and evaluating catalysts in optimizing hydrogen production from alkaline water electrolysis.

P-Doping Modulated RuIr Nanoparticles Anchored on Co/N/C Catalysts with Improved Alkaline Hydrogen Evolution Activity and Stability.

Achieving efficient and stable hydrogen evolution reactions in alkaline conditions is crucial for hydrogen production. In this study, a RuIr/Co(SA)NC-P catalyst featuring RuIr alloys alongside P-doping and CoNx sites is developed. RuIr alloying optimizes the electronic structure between Ru and Ir, promoting electron transfer from Ru to Ir. P-doping further modulates the electronic properties of RuIr alloys, optimizing hydrogen binding energy and weakening Ru─OH binding energy, facilitating rapid H2 generation and OHad transfer. Meanwhile, CoNx promotes water dissociation, providing a fast proton delivery path for RuIr alloys. The catalyst exhibits enhanced HER activity with a low overpotential of 20mV at 10mA cm-2, a Tafel slope of 20.4mV dec-1, and a turnover frequency of 19.5 H2 s-1 at 150mV overpotential. Moreover, catalyst stability is improved 8 times by mitigating RuIr alloy dissolution/agglomeration via P-doping. This work introduces a promising approach for developing efficient and stable HER electrocatalysts.

Ni2+ Ion-Induced Phase and Morphology Tailoring in Nix-CuMoSe Nanorod Catalysts for Overall Water Splitting.

Copper molybdenum-based selenides (CuMoSe) as promising hydrogen evolution catalysts have been widely applied in the electrocatalytic splitting of water, while their limited active sites and relatively poor oxygen evolution activity restrict their further application as effective bifunctional electrocatalysts. Here, we report a simple hydrothermal method to fabricate rodlike NiCuMoSe arrays on nickel foam (Nix-CuMoSe/NF), the morphology of which is determined by Ni2+ ions because Ni2+ can promote the growth of the rodlike structure. Furthermore, the phase transformation from CuSe to CuSe2 is triggered by adjusting the Ni2+ ion content of the growth solution. Due to the morphology control and phase component modulation, the prepared Ni2.5-CuMoSe/NF possesses effective catalytic activities of the hydrogen/oxygen evolution reaction (HER/OER) with overpotentials of 89/183 mV at 10 mA cm-2 in 1 M KOH, and the cell (composed of Ni2.5-CuMoSe/NF as both the cathode and anode) can provide a current density of 10 mA cm-2 at a low cell voltage of 1.50 V with a stability of 110 h. This work will advance the development of transition metal electrocatalysts for effective overall water splitting.

Enhanced photocatalytic hydrogen and oxygen evolution activity by two-dimensional van der Waals AlSb/ZnO heterostructure: A first-principles study

Photocatalytic water splitting facilitates the generation of green hydrogen energy by transforming renewable solar energy into chemical energy. This paper investigated the electronic, optical, and photocatalytic properties of AlSb/ZnO van der Waals (vDW) heterostructure using density functional theory. AlSb/ZnO, a semiconductor heterostructure with an indirect bandgap, was energetically stable with a formation energy of −0.4 eV as well as dynamically and thermally stable. The band edges of the 2D heterostructure maintained the essential redox energy levels for complete water splitting, allowing hydrogen and oxygen generation. Moreover, the heterostructure exhibited a high absorption coefficient in the visible region of the solar spectrum compared to the individual AlSb and ZnO monolayers. We revealed low barrier potential at neutral pH conditions for oxygen and hydrogen evolution reactions from the Gibbs free energy calculation without any external potential. Our study additionally showed the solar-to-hydrogen efficiency of 27.93% and a carrier utilization efficiency of 42.83%, indicating the AlSb/ZnO heterostructure as an excellent water splitting photocatalyst with remarkable potential for fuel cells and energy storage applications.

Domain-limited surface oxygen vacancy in rutile TiO2 for enhancing photocatalytic hydrogen evolution

Defect engineering is an effective strategy for enhancing the photocatalytic performance of semiconducting metal oxides. In this study, we demonstrate a simple method to engineer oxygen vacancies (OVs) on the surface of rutile TiO2 by the use of thiourea. No bulk phase defects or heteroatom doping are introduced during the hydrothermal reaction, while preserving the original morphology of rutile TiO2. It was observed that the structural synergies with surface OVs significantly alter the electronic structure, thereby extending the absorption region of rutile TiO2 and promoting efficient separation and transport of photogenerated carriers to the surface. The rutile TiO2 with OVs on its surface exhibits highly photocatalytic H2 evolution activity as 54.7 mmol·g-1·h-1 (with 1 wt% Pt loading), with an apparent quantum efficiency (AQY) of 24.7% at 380 nm.

Conjugated carbon network mediated - Graphdiyne based Cu2MoS4 homojunction for enhanced charge transfer dynamics

The preparation of stable and environment-friendly catalysts with high photocatalytic performance is of practical significance for the application of photocatalytic hydrogen evolution technology. Graphdiyne has a unique sp and sp2 hybrid structure, making it a potential photocatalyst due to its high surface carrier mobility and porous network structure. In this study, a Cu2MoS4 homojunction composite catalyst with conjugated carbon networks as electron transport channels was prepared by in situ solvothermal growth. Graphdiyne provides an additional pathway for photogenerated electron transfer, improving the efficiency of the interface charge separation. Simultaneously, the built-in electric field at the interface of Cu2MoS4 provides a strong driving force for electron transfer. Owing to the significant visible light absorption and effective multichannel transmission of photogenerated electrons, the Cu2MoS4/graphdiyne composite catalyst exhibited astonishing photocatalytic hydrogen evolution activity (11000 μmol g-1), which is 10 times that of Cu2MoS4 homojunction. Further experimental research and theoretical calculations provided effective evidence for the charge transfer pathway. This work provides a new strategy for constructing efficient hydrogen evolution photocatalysts and regulating the migration of photogenerated electrons.

Modulating Electronic Structure of MoS2 Nanosheets by Sulfide Enrichment‐Induced Vacancies for Enhanced Photocatalytic Hydrogen Production

AbstractEnhancing photocatalytic activity by changing the electronic structure of the catalyst is an effective strategy. 2H‐MoS2 has semiconductor properties, and its unsaturated side S atom is the main active site for its photocatalytic activity. However, due to the weak S─H bond energy, its hydrogen adsorption capacity is weak. In this work, the electronic structure of MoS2 is adjusted by S‐rich treatment, resulting in the formation of Mo vacancy (MoS2‐VMo). The level of Mo vacancies was assessed using UV–vis diffuse reflectance spectroscopy (UV–vis DRS). As these vacancies can capture certain photogenerated electrons, thereby reducing the recombination of electron‐hole pairs. Through DFT calculation, it is found that the antibonding orbital electron filling of MoS2‐VMo is weakened, the bond energy of S─Mo bond is weakened, and the bond energy between S─H bond is enhanced, which is more conducive to proton adsorption. The photocatalytic activity for hydrogen evolution of MoS2‐3, which underwent the optimal S‐rich treatment, achieved a remarkable rate of 2404.6 µmol g−1 h−1 in dye eosin Y (EY) sensitization system, significantly surpassing that of MoS2 lacking the S‐enriched treatment. This study introduces a novel concept for enhancing the photocatalytic hydrogen evolution performance of metal sulfides via defect engineering.

One pot synthesis of donor-acceptor carbon nitride with distinct thiophene rings accelerate photocatalytic hydrogen evolution

Graphitic carbon nitride (g-CN) with a donor-acceptor structure was synthesized by urea and cross-linking thiophene precursors at the terminal sites, achieved through calcination of urea with four different thiophene-based precursors under atmospheric conditions. Among these, UDB-2-1, which incorporates dibenzothiophene-2-carboxyaldehyde (DB-2) 1 mg, demonstrated a hydrogen evolution activity of 650 μmol/g·h, approximately six times higher than pristine graphitic carbon nitride (U). The apparent quantum yield (AQY) was measured to be 4.01 %, 4.89 %, and 3.72 % at 400 nm, 420 nm, and 450 nm, respectively, in the presence of potassium hydrogen phosphate (KPH). This enhanced performance is attributed to increased visible light absorption from the n-π∗ transition introduced by the thiophene ring and enhanced charge separation due to the donor-acceptor (DA) structure, with DB-2 acting as an electron donor. Prepared photocatalysts were characterized by XRD, XPS, FTIR, SEM, TEM, BET, ESR, EIS, Mott-Schottky, DRS, PL, and TRPL measurement. This study provides a simple and effective strategy to improve carbon nitride performance and underscores the importance of functional group positioning and structural isomers in molecular design for solar-energy applications.

New insights into rice starch-gallic acid-whey protein isolate interactions: Effects of multiscale structural evolution and enzyme activity on starch digestibility

In starch-based food where proteins and polyphenols coexist, the impact of protein on the inhibition of starch digestion by polyphenols is unclear. Therefore, the aim of this study was to investigate the impact of whey protein isolate (WPI) on the inhibition of rice starch digestion by gallic acid (GA) from the aspects of multiscale structure and enzyme activity. Rice starch-gallic acid-whey protein isolate complex (RS-GA-WPI) was formed predominantly by hydrogen bonding and hydrophobic interactions. Compared to rice starch-gallic acid complex (RS-GA), RS-GA-WPI exhibited higher short-range ordering and thermal stability, and lower relative crystallinity. Fluorescence spectra and molecular docking showed that the interactions between GA and WPI weakened the hydrogen bond between GA and enzyme active site, so that WPI significantly reduced the enzyme inhibitory activity of GA. The above factors led to the result that the presence of WPI weakened the inhibitory effect of GA on starch digestibility. RS-GA-WPI showed higher starch digestibility and lower resistant starch content compared to RS-GA. This study provided a new understanding of starch digestion mechanism in starch-polyphenol-protein coexistence system.

High stability cubic perovskite Sr0.9Y0.1Co1-xFexO3-δ oxygen evolution by phase control and electrochemical reconstruction

Transition metal oxides are considered ideal electrocatalyst materials due to their low cost and high intrinsic activity. Among them, SrCoO3-δ has received increasing attention due to its multi-phase structure and tunable electronic properties, though its OER reaction kinetics and catalysis stability are unsatisfactory. Herein, based on a simple one-step solid-state reaction method, we use a small amount of rare earth Y ions (10 %) to transform H-SCO2.52 from a hexagonal structure to a stable cubic perovskite Sr0.9Y0.1CoO3−δ. While broadening the atomic ratio of Co and Fe in the B-site under the cubic perovskite Sr0.9Y0.1Co1-xFexO3−δ (x = 0–1), the relationship between the B-site electronic state, oxygen vacancies, and OER performance has been explored. Sr0.9Y0.1Co0.2Fe0.8O3−δ with a high concentration of oxygen vacancies, exhibits the lowest overpotential of 277 mV and maintains stability at 10 mA cm−2 for 88 h. The valence states of Fe and Co atoms in SYC0.2F0.8 O are optimized (Fe2+∼50.81 %, Co2+∼19.39 %), and the oxygen evolution activity is enhanced by electrochemical reconfiguration to form high-valence Fe and Co ions. Selective leaching of Sr ions via electrochemical surface reconstruction activates FeOOH and CoOOH amorphous layer active sites on the catalyst surface, significantly enhancing reaction kinetics.

Catalytic charge synergy on Ni/Sr@rTiO2 system to promote hydrogen evolution for the implementation of green energy technologies

This study demonstrates an effective and sustainable approach for hydrogen production to the practical implementation of green energy technologies. For this purpose, extremely stable catalysts Ni/Sr@rTiO2 have been synthesized and evaluated for hydrogen evolution reactions. Optical and structural characteristics of catalysts have been evaluated via advanced analytical techniques. These techniques include XRD, UV–Vis/DRS, PL, FT-IR, Raman, SEM, AFM and TEM. Surface area and porosity were obtained with BET while, chemical compositions of catalysts were authenticated via EDX, and XPS. All photoreaction was done in 150 mL reactor (Quartz). Hydrogen evolution activities were examined on GC-TCD (Shimadzu-2010/Japan). Results indicate that bare rutile titanium dioxide (rTiO2) and Ni1.5/Sr0.5@rTiO2 have delivered 0.20 mmol g−1h−1 and 35.14 mmol g−1h−1 of hydrogen respectively. Higher activities (i.e. in case of Ni1.5/Sr0.5@rTiO2) were attributed to the rapid charge transfer on active sites i.e. Ni metal centers. It has been predicted that presence of strontium promotes electrons to the conduction bands of rTiO2; hence favor to elevate the electronic pools so that they can progressively involve for water reduction. The results revealed that Ni1.5/Sr0.5@rTiO2 exhibit higher charge separation relative to the bare rTiO2. It has been noted that formation of synergy for the electron quenching and utilization is main cause of higher hydrogen evolution that is due to presence of nickel and strontium. On the basis of results, it has been concluded that catalyst reported herein has potential to replace the expensive and traditional catalysts associated with hydrogen generation technologies.

Metal Single Atom-Hydroxyl Incorporation in Poly(heptazine imide) to Create Active Sites for Photocatalytic Water Oxidation.

Poly(heptazine imide) (PHI) salts are extensively researched crystalline carbon nitride photocatalysts, but their photocatalytic water oxidation (PWO) performance is scarcely researched because of the difficulty in creating efficient active sites. Interference of metal ion (e.g., Na+ and K+) loss from the PHI salts in their PWO research has hardly been considered. Herein, metal single atom─OH (e.g., Co─OH) groups are incorporated into PHI to create efficient PWO active sites, via simple ion metathesis, hydrolysis, and deprotonation. The Co─OH modified PHI exhibits 9.3-fold higher PWO (oxygen evolution) activity than PHI, with an external quantum yield reaching 0.44% even at 600 nm. Excluding interference of the metal ion loss, the function of the Co─OH incorporation is evidenced mainly to facilitate the oxygen evolution reaction, as well as to promote photogenerated charge separation and raise visible light absorption, with the role of the OH especially revealed. Moreover, it is discovered that Na+ loss from sodium PHI will decrease its PWO activity, protonation of PHI has a detrimental effect on its PWO performance, and some other metal single atom─OH incorporation in PHI can also enhance its PWO activity. Overall, this work provides a general way to create PWO active sites in PHI.

Hydrothermal-Induced Cationic Vacancies in NiAl Hydroxide for Enhanced Oxygen Evolution Activities through Optimization of eg* Band Broadening.

Nickel-based hydroxides [Ni(OH)2] have attracted significant attention as effective oxygen evolution reaction (OER) catalysts. In recent years, defect engineering has been extensively utilized in Ni(OH)2 modification research. Numerous studies have confirmed that the generation of defects can expose more active sites and regulate electronic states, particularly through the introduction of Al cationic vacancies, which enhance conductivity and thereby improve the catalytic performance. The traditional method for producing cationic vacancies is electrochemical etching. However, this method generates a limited number of vacancies in the catalysts and has the complex etching process. Herein, we found that when NiAl layered double hydroxides were treated using a hydrothermal process at 100 °C in a KOH solution, more Al cationic vacancies were generated. Compared to the traditional method with an Al leaching efficiency of 24%, our proposed method achieved an Al leaching efficiency of 44%. Meanwhile, the electrochemical results showed that the overpotential was reduced by 110 mV at 10 A/g. Further experiments showed that the enhanced OER activities resulting from an increased number of cationic defects lead to structural distortions, which broaden the eg* band, significantly affecting the rate of electron transfer between the electrocatalyst and external circuitry, thereby enhancing the OER activity. This work presents a promising approach to creating cationic defects in Ni(OH)2 for high-performance electrocatalysts.

Electronic Structure Modulating of W18O49 Nanospheres by Niobium Doping for Efficient Hydrogen Evolution Reaction.

Hydrogen, known for its high energy density and environmental benefits, serves as a prime substitute for fossil fuels. Nonetheless, the hydrogen evolution reaction (HER), essential in electrolysis, encounters challenges with slow kinetics and significant overpotential, which elevate costs and reduce efficiency. Thus, developing efficient electrocatalysts to reduce HER overpotential is vital to enhance hydrogen production efficiency and minimize energy consumption. Adjusting the electronic structure of transition metal oxides via elemental doping is a potent strategy to improve the effectiveness of electrocatalysts for hydrogen evolution. In this work, we synthesized a set of niobium-doped tungsten oxides (Nbx-W18O49) under anoxic conditions using a straightforward "one-pot" solvothermal approach. After doping Nb, the oxygen vacancy content inside W18O49 was increased, which induced a synergistic effect with the active sites of tungsten. In acidic environments, the hydrogen evolution activity of the Nb0.6-W18O49 electrocatalyst is second only by 20 wt % Pt/C. It attains a current density of -10 mA cm-2 at an overpotential of 102 mV. By comparison with W18O49, Nb0.4-W18O49 and Nb0.5-W18O49, Nb0.6-W18O49 demonstrates a reduced charge transfer resistance, which significantly enhances its conductivity and the speed of electron movement across interfaces. Coupled with this feature are notably faster HER kinetics. Additionally, it exhibits excellent stability, meaning it maintains its performance and structural integrity over prolonged periods and under various operational conditions. This article provides a new perspective for discovering inexpensive and efficient hydrogen evolution electrocatalyst materials.

Heterostructuring Uniform 2D CdS on Ru/Ti3C2-TiO2 via In situ Oxidized Ru-Loaded MXene for Boosting Photocatalytic H2 Production.

Building heterojunctions and exposing more catalytic active sites are effective strategies to enhance the photocatalytic hydrogen evolution activity. Herein, TiO2 nanosheets are oxidized in situ on Ru-loaded MXene as carriers and subsequently loaded with uniform 2D CdS via hydrothermal method to obtain 2D Ru/Ti3C2-TiO2/CdS composite photocatalysts that integrate heterojunctions and cocatalysts. The formation of heterojunction between CdS and TiO2 is conducive to promoting the separation and transfer of photogenerated charges, simultaneously, Ru/Ti3C2 with the fully exposed Ru and Ti3C2 can act as effective active sites of photocatalytic hydrogen production reaction. The composite photocatalyst exhibits an improved hydrogen production rate with 5479µmol g-1 h-1, which is 5, 3, and four times more than that of pristine CdS, CdS loaded Ti3C2-TiO2and CdS loaded Ru-TiO2 respectively. The results reveal that the notable enhancement in performance can primarily be ascribed to the introduction of the TiO2/CdS heterojunction and the efficient cocatalysts of Ru/Ti3C2. Moreover, the 2D Ti3C2 with high conductivity as carriers can increase charge transfer, and its 2D structure can serve as a template for growing 2D photocatalysts with higher activity. The interface engineering with multiple interfaces can offer novel insights for the advancement of efficient hydrogen evolution reaction catalysts.

Achieving Excellent H2 Evolution Activity of Silver Nanocatalyst by a Simple Electrochemical Treatment Process.

Silver nanoparticles (AgNPs) were synthesized in an aqueous solution via the reduction of AgNO3 employing citrate reducing agent. The resultant AgNPs were first assayed for the catalytic H2 evolution in an acidic electrolyte, namely pH 0.3 H2SO4 solution, showing negligible activity. The AgNPs were then conditioned in the same electrolyte solution while repeating the cyclic potential polarization between -0.25 V and 0.95 V (or 1.8 V) versus RHE. Effects of the electrochemical treatment to the morphology, crystalline, surface chemistry and H2 evolution catalytic activity of AgNPs were examined. It was found that the electrochemical treatment remarkably boosted the H2 evolution catalytic activity of AgNPs. The electrochemically activated AgNPs represents an attractive Pt-free catalyst for the H2 evolution in acidic medium.

I3‐‐Mediated Oxygen Evolution Activities to Boost Rechargeable Zinc‐Air Battery Performance with Low Charging Voltage and Long Cycling Life

An effective strategy to facilitate oxygen redox chemistry in metal‐air batteries is to introduce a redox mediator into the liquid electrolyte. The rational utilization of redox mediators to accelerate the charging kinetics while ensuring the long lifetime of alkaline Zn‐air batteries is challenging. Here, we apply commercial acetylene black catalysts to achieve an I3‐‐mediated Zn‐air battery by using ZnI2 additives that provide I3‐ to accelerate the cathodic redox chemistry and regulate the uniform deposition of Zn2+ on the anode. The Zn‐air battery performs an ultra‐long cycle life of over 600 h at 5 mA cm‐2 with a final charge voltage of 1.87 V. We demonstrate that I‐ mainly generates I3‐ on the surface of carbon catalysts during the electrochemically charging process, which can further chemically react with OH‐ to generate oxygen and further revert to I‐, thus obtaining a stable electrochemical system. This work offers a strategy to simultaneously improve the cycling life and reduce the charging voltage of Zn‐air batteries through redox mediator methods.

I3 --Mediated Oxygen Evolution Activities to Boost Rechargeable Zinc-Air Battery Performance with Low Charging Voltage and Long Cycling Life.

An effective strategy to facilitate oxygen redox chemistry in metal-air batteries is to introduce a redox mediator into the liquid electrolyte. The rational utilization of redox mediators to accelerate the charging kinetics while ensuring the long lifetime of alkaline Zn-air batteries is challenging. Here, we apply commercial acetylene black catalysts to achieve an I3 --mediated Zn-air battery by using ZnI2 additives that provide I3 - to accelerate the cathodic redox chemistry and regulate the uniform deposition of Zn2+ on the anode. The Zn-air battery performs an ultra-long cycle life of over 600 h at 5 mA cm-2 with a final charge voltage of 1.87 V. We demonstrate that I- mainly generates I3 - on the surface of carbon catalysts during the electrochemically charging process, which can further chemically react with OH- to generate oxygen and further revert to I-, thus obtaining a stable electrochemical system. This work offers a strategy to simultaneously improve the cycling life and reduce the charging voltage of Zn-air batteries through redox mediator methods.

N, S, P co-doped Co/Co3O4/C particles on carbon fiber paper as a self-supported bifunctional catalyst for direct seawater splitting

To optimize the distribution and transportation of electrical energy, converting surplus or low-quality electricity through electrocatalytic seawater splitting to produce hydrogen is an ideal method. In this work, we developed a bifunctional electrocatalyst (ZIF-9/CP-S-P) through the in-situ growth of ZIF-9 on the carbon fiber paper (CP), followed by sequential sulfurization and phosphidation. This catalyst achieves stable hydrogen and oxygen production in natural seawater, displaying outstanding oxygen evolution activity with an overpotential of just 390mV at 10mA/cm² (Tafel slope: 426.5mV/dec) and impressive hydrogen evolution activity with an overpotential of only 578mV at 10mA/cm² (Tafel slope: 287.7mV/dec). The two-electrode electrolyzer assembled by ZIF-9/CP-S-P || ZIF-9/CP-S-P was conducted the chronoamperometry test for 20000s in 1M phosphate buffer solution and for 100000s in natural seawater, and its performance was comparable to that of commercial Pt/C || IrO2. These findings indicate the potential of ZIF-9/CP-S-P catalyst for practical applications in direct seawater splitting to produce hydrogen and oxygen.