Rom Tanmay, Agrawal Anant, Biswas Rathindranath, Haldar Krishna Kanta, Paul Avijit Kumar
Department of Chemistry, National Institute of Technology, Kurukshetra136119, India.
Chemistry and Physics of Materials Unit, School of Advanced Materials (SAMat), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bengaluru 560064, Karnataka, India.
ACS Appl Mater Interfaces. 2024 Apr 10;16(14):17797-17811. doi: 10.1021/acsami.3c19079. Epub 2024 Mar 29.
The design and exploration of advanced materials as a durable multifunctional electrocatalyst toward sustainable energy generation and storage development is the most perdurable challenge in the domain of renewable energy research. Herein, a facile in situ solvothermal approach has been adopted to prepare a methylviologen-regulated crystalline metal phosphonate compound, [CHN][Ni(CHN)(Hhedp)]•6HO (), (Hhedp = 1-hydroxyethane 1,1-diphosphonic acid) and well characterized by several techniques. The as-prepared displays excellent bifunctional electrocatalytic activity with dynamic stability toward oxygen evolution reaction (η = 288 mV) and hydrogen evolution reaction (η = 228 mV) in alkaline (1.0 M KOH) and acidic mediums (0.5 M HSO), respectively. Such a low overpotential and Tafel slope (68 mV/dec for OER; 56 mV/dec for HER) along with long-term durability up to 20 h of make it superior to benchmark the electrocatalyst and various nonprecious metal-based catalysts under similar experimental condition. Further, the electrochemical supercapacitor measurements (in three-electrode system) reveal that the electrode possesses much higher specific capacity of 187.6 C g at a current density of 2 A g (272 C g at 5 mV s) with capacitance retention of 75.2% over 10,000 cycles at 14 A g (Coulombic efficiency > 99%) in 6 M KOH electrolyte medium. Finally for a practical application, an asymmetric supercapacitor device (coin cell) is assembled by material. The as-fabricated device delivers the maximum energy density of 39.4 Wh kg at a power density of 450 W kg and achieves a wide voltage window of 1.80 V. Notably, the device endures a remarkable cycle performance with cyclic retention of 92% (Coulombic efficiency > 99%) even after 14,000 charge/discharge cycles at 10 A g. Nevertheless, the extraordinary electrochemical activities toward OER and HER as well as the high-performance device fabrication for LED illumination of such a noble metal-free lower-dimensional charge-transfer compound are truly path breaking and would be promising for the development of advanced multifunctional materials.
设计和探索先进材料作为一种耐用的多功能电催化剂以实现可持续能源的产生和存储发展，是可再生能源研究领域最持久的挑战。在此，采用了一种简便的原位溶剂热法制备了一种甲基紫精调控的结晶金属膦酸盐化合物，[CHN][Ni(CHN)(Hhedp)]•6HO （），（Hhedp = 1-羟基乙烷-1,1-二膦酸），并通过多种技术对其进行了充分表征。所制备的材料在碱性（1.0 M KOH）和酸性介质（0.5 M HSO）中分别对析氧反应（η = 288 mV）和析氢反应（η = 228 mV）表现出优异的双功能电催化活性及动态稳定性。如此低的过电位和塔菲尔斜率（析氧反应为68 mV/dec；析氢反应为56 mV/dec）以及长达20小时的长期耐久性，使其在类似实验条件下优于基准电催化剂和各种非贵金属基催化剂。此外，电化学超级电容器测量（在三电极体系中）表明，在6 M KOH电解质介质中，该材料电极在2 A g的电流密度下具有高达187.6 C g的比容量（在5 mV s时为272 C g），在14 A g下经过10000次循环后电容保持率为75.2%（库仑效率> 99%）。最后，为了实际应用，用该材料组装了一个不对称超级电容器器件（硬币电池）。所制备的器件在450 W kg的功率密度下提供了39.4 Wh kg的最大能量密度，并实现了1.80 V的宽电压窗口。值得注意的是，即使在10 A g下经过14000次充放电循环后，该器件仍具有显著的循环性能，循环保持率为92%（库仑效率> 99%）。尽管如此，这种无贵金属的低维电荷转移化合物对析氧反应和析氢反应具有非凡的电化学活性以及用于LED照明的高性能器件制造，确实具有开创性意义，并且对先进多功能材料的发展具有广阔前景。
