A steady composite molecular anode Ru1/MWCNTsCOOH/GC for robust catalytic water oxidation

Abstract Development of efficient molecular devices for overall water splitting has always been a hotspot of research to realize clean and sustainable energy conversion. In the case, long-term durability of molecular devices is a crucial factor to determine their practical application. Here, an efficient composite molecular anode was assembled by immobilization of charge-neutral mononuclear Ru1 complex on COOH-functionalized multiwalled carbon nanotubes (MWCNTsCOOH) sticking on a glassy carbon (GC) electrode ( Ru1 /MWCNTsCOOH/GC). The prepared hybrid anode showed a low onset overpotential of only 380 mV for electrocatalytic water oxidation. Moreover, the anode displayed a steady catalytic current density of 1.25 mA/cm 2 for more than 5 h at the overpotential of 580 mV, a high TON of 186000 (5 h), a TOF of 10.3 s −1 and a faradic efficiency of 96%, indicating the significant efficiency and extremely durability. The excellent durability of the molecular anode should be attributed to the key charge-neutral catalytic intermediates ( Ru1a∼d ) of the catalytic step and the two long flexible carbon chains of the catalyst.