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2024 Volume 43 Issue 1
2024, 43(1): 100191
doi: 10.1016/j.cjsc.2023.100191
Abstract:
In the domain of acidic water splitting, designing bifunctional catalysts that marry high activity with enduring stability is a formidable challenge. Herein, we have constructed platinum-containing ruthenium oxide nanoparticles (Pt@RuOx NPs) to achieve excellent overall water splitting performance in acidic electrolytes. Pt@RuOx NPs demonstrate exceptional catalytic activity for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in acidic seawater, requiring overpotentials of only 20 and 157 mV, respectively to achieve a current density of 10 mA cm-2. Furthermore, in 0.5 M H2SO4, this catalyst exhibits high HER (19 mV) and OER (236 mV) catalytic activities. The two-electrode water splitting system composed of bifunctional Pt@RuOx NPs requires cell voltages of only 1.442 and 1.465 V to deliver a current density of 10 mA cm-2 in acidic seawater and 0.5 M H2SO4. Remarkably, this catalyst displays remarkable stability in the water splitting process. It is shown that the introduction of Pt could augment oxygen vacancies and enhance catalytic activity significantly. The synergy between Pt and Ru further contributes to the improved performance. Additionally, we have observed that acidic seawater holds distinct advantages for acidic water splitting, along with a thorough exploration of the relationship between Cl- concentration and catalytic performance. This study not only provides a strategy to improve the catalytic activity and stability of ruthenium-based catalysts for water splitting in acidic environments, but also unveils the promoting effect of Cl- on the catalytic activity in acidic water splitting.
In the domain of acidic water splitting, designing bifunctional catalysts that marry high activity with enduring stability is a formidable challenge. Herein, we have constructed platinum-containing ruthenium oxide nanoparticles (Pt@RuOx NPs) to achieve excellent overall water splitting performance in acidic electrolytes. Pt@RuOx NPs demonstrate exceptional catalytic activity for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in acidic seawater, requiring overpotentials of only 20 and 157 mV, respectively to achieve a current density of 10 mA cm-2. Furthermore, in 0.5 M H2SO4, this catalyst exhibits high HER (19 mV) and OER (236 mV) catalytic activities. The two-electrode water splitting system composed of bifunctional Pt@RuOx NPs requires cell voltages of only 1.442 and 1.465 V to deliver a current density of 10 mA cm-2 in acidic seawater and 0.5 M H2SO4. Remarkably, this catalyst displays remarkable stability in the water splitting process. It is shown that the introduction of Pt could augment oxygen vacancies and enhance catalytic activity significantly. The synergy between Pt and Ru further contributes to the improved performance. Additionally, we have observed that acidic seawater holds distinct advantages for acidic water splitting, along with a thorough exploration of the relationship between Cl- concentration and catalytic performance. This study not only provides a strategy to improve the catalytic activity and stability of ruthenium-based catalysts for water splitting in acidic environments, but also unveils the promoting effect of Cl- on the catalytic activity in acidic water splitting.
2024, 43(1): 100192
doi: 10.1016/j.cjsc.2023.100192
Abstract:
Due to their high energy density and low price, aqueous polysulfide/iodide redox flow batteries are appealing for scalable energy storage. However, the greatest barrier to their practical uses is the low electrochemical kinetics of the redox reactions of polysulfide ions on graphite electrodes, which often limit their energy efficiency and power density. In this study, the CuFeS2 nanomaterial was successfully synthesized through the hot injection method, and CuFeS2 nanomaterials were uniformly coated onto the surfaces and sandwiched into graphite felt (GF); this process can significantly boost the electrocatalytic activities of S2-/Sx2- redox reactions by improving the charge transfer process, which has been proven by the electrochemical measurement and density functional theory (DFT) simulations. The polysulfide-iodide flow battery, with GF-CuFeS2 serving as the negative electrode, can achieve a high energy efficiency of 79.6% at 20 mA/cm2, a power density of 50.7 mW/cm2, and a stable energy efficiency retention of 87.0% after 180 cycles.
Due to their high energy density and low price, aqueous polysulfide/iodide redox flow batteries are appealing for scalable energy storage. However, the greatest barrier to their practical uses is the low electrochemical kinetics of the redox reactions of polysulfide ions on graphite electrodes, which often limit their energy efficiency and power density. In this study, the CuFeS2 nanomaterial was successfully synthesized through the hot injection method, and CuFeS2 nanomaterials were uniformly coated onto the surfaces and sandwiched into graphite felt (GF); this process can significantly boost the electrocatalytic activities of S2-/Sx2- redox reactions by improving the charge transfer process, which has been proven by the electrochemical measurement and density functional theory (DFT) simulations. The polysulfide-iodide flow battery, with GF-CuFeS2 serving as the negative electrode, can achieve a high energy efficiency of 79.6% at 20 mA/cm2, a power density of 50.7 mW/cm2, and a stable energy efficiency retention of 87.0% after 180 cycles.
2024, 43(1): 100193
doi: 10.1016/j.cjsc.2023.100193
Abstract:
SACs have been emerged as a promising alternative to traditional catalysts due to their exceptional activity and selectivity for ECO2RR. Compared to traditional catalysts, SACs are composed of individual metal atoms that are strongly attached to the supporting material. This distinctive feature significantly improves their activity. In addition, SACs have remarkable efficiency in converting CO2 into important chemicals and fuels, exhibiting enhanced selectivity for precise products, such as CH4 or CO. The high selectivity of SACs reduces the formation of undesirable byproducts, making them a sustainable choice for tackling CO2 emissions and aiding the shift towards a more carbon-neutral energy economy.
SACs have been emerged as a promising alternative to traditional catalysts due to their exceptional activity and selectivity for ECO2RR. Compared to traditional catalysts, SACs are composed of individual metal atoms that are strongly attached to the supporting material. This distinctive feature significantly improves their activity. In addition, SACs have remarkable efficiency in converting CO2 into important chemicals and fuels, exhibiting enhanced selectivity for precise products, such as CH4 or CO. The high selectivity of SACs reduces the formation of undesirable byproducts, making them a sustainable choice for tackling CO2 emissions and aiding the shift towards a more carbon-neutral energy economy.
2024, 43(1): 100195
doi: 10.1016/j.cjsc.2023.100195
Abstract:
This work demonstrates that the introduction of photocatalysts is an effective strategy to enhance the thermopower of thermogalvanic cells. Meanwhile, this pioneering system combines the generation of electricity with the production of H2, harnessing energy from solar radiation. Future research in this field will be delved into investigating alternative photocatalysts and redox couples, thereby further improving the efficiency of energy conversion.
This work demonstrates that the introduction of photocatalysts is an effective strategy to enhance the thermopower of thermogalvanic cells. Meanwhile, this pioneering system combines the generation of electricity with the production of H2, harnessing energy from solar radiation. Future research in this field will be delved into investigating alternative photocatalysts and redox couples, thereby further improving the efficiency of energy conversion.
2024, 43(1): 100197
doi: 10.1016/j.cjsc.2023.100197
Abstract:
Atomic catalysts (ACs) have been considered as promising catalysts for efficient hydrogen production through water splitting. Herein, we report an AC with single Mn atoms highly dispersed on the surface of graphdiyne-coated copper hydroxide nanowire arrays (Mn-GDY/Cu(OH)x NWs). By anchoring Mn atoms on GDY, the specific surface area, the number of active sites, and the stability of catalyst are greatly improved. Detailed characterizations reveal that the high hydrogen and oxygen evolution reaction (HER/OER) catalytic activity of the catalyst is induced by strong incomplete charge transfer effect between the metal atoms and GDY. These advantages enable the electrocatalysts to drive a current density of 10 mA cm-2 at low overpotentials of 188 and 130 mV for OER and HER, respectively, together with excellent long-term stability. Remarkably, the alkaline electrolyzer using Mn-GDY/Cu(OH)x as both cathode and anode electrodes can reach 10 mA cm-2 only at a much low cell voltage of 1.50 V.
Atomic catalysts (ACs) have been considered as promising catalysts for efficient hydrogen production through water splitting. Herein, we report an AC with single Mn atoms highly dispersed on the surface of graphdiyne-coated copper hydroxide nanowire arrays (Mn-GDY/Cu(OH)x NWs). By anchoring Mn atoms on GDY, the specific surface area, the number of active sites, and the stability of catalyst are greatly improved. Detailed characterizations reveal that the high hydrogen and oxygen evolution reaction (HER/OER) catalytic activity of the catalyst is induced by strong incomplete charge transfer effect between the metal atoms and GDY. These advantages enable the electrocatalysts to drive a current density of 10 mA cm-2 at low overpotentials of 188 and 130 mV for OER and HER, respectively, together with excellent long-term stability. Remarkably, the alkaline electrolyzer using Mn-GDY/Cu(OH)x as both cathode and anode electrodes can reach 10 mA cm-2 only at a much low cell voltage of 1.50 V.
2024, 43(1): 100199
doi: 10.1016/j.cjsc.2023.100199
Abstract:
As an oxygen reduction reaction (ORR) catalyst, nitrogen-doped carbon (NC) is widely used in zinc-air batteries (ZABs). However, NC catalysts exhibit low conductivity and insufficient exposure of active sites. Therefore, a Co-based deep eutectic solvent (DES) was selected to modify NC catalyst (Co-NC) to improve ORR performances. Density functional theory (DFT) calculation shows that the modification of Co-based DES can change the electronic structure of NC and increase metallic active sites, which is beneficial to the desorption of reaction intermediates on Co-NC, further improving ORR performance. Co-NC shows excellent ORR performances and stability. Impressively, ZABs assembled with Co-NC manifest a high maximum power density of 177.4 mW cm-2, a high specific capacity of 726.12 mA h g-1 and a charge-discharge cycle life of 500 h. This study can provide practical reference for surface modified carbon-based electrocatalyst with DES to improve ORR performances.
As an oxygen reduction reaction (ORR) catalyst, nitrogen-doped carbon (NC) is widely used in zinc-air batteries (ZABs). However, NC catalysts exhibit low conductivity and insufficient exposure of active sites. Therefore, a Co-based deep eutectic solvent (DES) was selected to modify NC catalyst (Co-NC) to improve ORR performances. Density functional theory (DFT) calculation shows that the modification of Co-based DES can change the electronic structure of NC and increase metallic active sites, which is beneficial to the desorption of reaction intermediates on Co-NC, further improving ORR performance. Co-NC shows excellent ORR performances and stability. Impressively, ZABs assembled with Co-NC manifest a high maximum power density of 177.4 mW cm-2, a high specific capacity of 726.12 mA h g-1 and a charge-discharge cycle life of 500 h. This study can provide practical reference for surface modified carbon-based electrocatalyst with DES to improve ORR performances.
2024, 43(1): 100200
doi: 10.1016/j.cjsc.2023.100200
Abstract:
Nickel iron (hydroxyl) hydroxide with unique layered structure and controllable composition is widely regarded as typical oxygen evolution reaction (OER) catalysts. Recently, developing top-down approaches to realize the facile preparation of transition metal hydroxide catalyst has received wide attention. Based on the natural microorganism corrosion behavior, this work demonstrates the external magnetic field-assisted microbial corrosion strategy to construct advanced transition metal hydroxide OER catalyst, and the prepared biofilm electrode presents superior OER performance in the existence of magnetic field, which needs an overpotential of 287 mV at 100 mA cm-2. Experimental and theoretical calculations show the applied magnetic field can accelerate sulfate reducing bacteria (SRB) corrosion and chemical corrosion. The additional magnetic field can promote SRB corrosion to produce FeS, which can facilitate the optimization of O intermediate desorption from the NiOOH catalyst during OER process, reducing the reaction energy barrier for O→OOH. The synergistic effect between the nickel-iron oxyhydroxides originated from the accelerated chemical corrosion and FeS produced from the accelerated SRB corrosion interprets the improved OER activity. This work explores the influence of magnetic field on the construction of advanced OER materials, which can provide an effective magnetic field-assisted corrosion engineering strategy, and promote the development of multidisciplinary fields of physics, biology, and emerging energy conversion technologies.
Nickel iron (hydroxyl) hydroxide with unique layered structure and controllable composition is widely regarded as typical oxygen evolution reaction (OER) catalysts. Recently, developing top-down approaches to realize the facile preparation of transition metal hydroxide catalyst has received wide attention. Based on the natural microorganism corrosion behavior, this work demonstrates the external magnetic field-assisted microbial corrosion strategy to construct advanced transition metal hydroxide OER catalyst, and the prepared biofilm electrode presents superior OER performance in the existence of magnetic field, which needs an overpotential of 287 mV at 100 mA cm-2. Experimental and theoretical calculations show the applied magnetic field can accelerate sulfate reducing bacteria (SRB) corrosion and chemical corrosion. The additional magnetic field can promote SRB corrosion to produce FeS, which can facilitate the optimization of O intermediate desorption from the NiOOH catalyst during OER process, reducing the reaction energy barrier for O→OOH. The synergistic effect between the nickel-iron oxyhydroxides originated from the accelerated chemical corrosion and FeS produced from the accelerated SRB corrosion interprets the improved OER activity. This work explores the influence of magnetic field on the construction of advanced OER materials, which can provide an effective magnetic field-assisted corrosion engineering strategy, and promote the development of multidisciplinary fields of physics, biology, and emerging energy conversion technologies.
2024, 43(1): 100210
doi: 10.1016/j.cjsc.2023.100210
Abstract:
Defect engineering on metal-organic frameworks (MOFs) provides high flexibility to rationally design advanced oxygen evolution reaction (OER) catalysts with low overpotential and high stability. However, fundamental understanding the effect of defect concentration on catalytic OER activity is still quite ambiguous. Herein, the Co-MOF-Dx catalysts with regulated oxygen defects concentration are deliberately constructed via coupling one-pot solvothermal synthesis with NaBH4 chemical reduction process. Experimental findings propose that the oxygen defect concentration within Co-MOF-Dx gradually increases with raising the NaBH4 content, which could provide a flexible platform to tailor the electronic structure around active Co site and optimize adsorption/desorption capacity of oxygen intermediates. When the introduction content of NaBH4 is up to 5 mg, the resulting abundant unsaturated coordination defects could endow the Co-MOF-D5 catalyst with optimized electronic structure and more exposed active sites for improving charge transfer and adsorption/desorption capacity. It is found that the optimized Co-MOF-D5 can drive the current density of 10 mA cm-2 only at a low overpotential of 300 mV with the small Tafel slope of 53.1 mV dec-1 in alkaline medium. This work sheds light on the way for the development of high-performance MOF catalysts via modulating defect concentration.
Defect engineering on metal-organic frameworks (MOFs) provides high flexibility to rationally design advanced oxygen evolution reaction (OER) catalysts with low overpotential and high stability. However, fundamental understanding the effect of defect concentration on catalytic OER activity is still quite ambiguous. Herein, the Co-MOF-Dx catalysts with regulated oxygen defects concentration are deliberately constructed via coupling one-pot solvothermal synthesis with NaBH4 chemical reduction process. Experimental findings propose that the oxygen defect concentration within Co-MOF-Dx gradually increases with raising the NaBH4 content, which could provide a flexible platform to tailor the electronic structure around active Co site and optimize adsorption/desorption capacity of oxygen intermediates. When the introduction content of NaBH4 is up to 5 mg, the resulting abundant unsaturated coordination defects could endow the Co-MOF-D5 catalyst with optimized electronic structure and more exposed active sites for improving charge transfer and adsorption/desorption capacity. It is found that the optimized Co-MOF-D5 can drive the current density of 10 mA cm-2 only at a low overpotential of 300 mV with the small Tafel slope of 53.1 mV dec-1 in alkaline medium. This work sheds light on the way for the development of high-performance MOF catalysts via modulating defect concentration.
