Amorphous (Fe)Ni-MOF-derived hollow (bi)metal/oxide@N-graphene polyhedron as effectively bifunctional catalysts in overall alkaline water splitting

Fe/Ni Bimetallic Organic Framework Deposited on TiO2 Nanotube Array for Enhancing Higher and Stable Photoelectrochemical Activity of Oxygen Evaluation Reaction

“…Therefore, the search for active, stable, and cost-efficient non-precious metal-based electrocatalysts for hydrogen evolution via water splitting is urgently needed to make a substantial improvement on energy technologies. In particular, photoelectrochemical (PEC) devices have recently been regarded as a promising method of converting solar to hydrogen energy and the PEC water oxidation using light- harvesting semiconductor- like TiO 2 nanomaterials [ 9 , 10 , 11 ] and metal– organic frameworks (MOFs) [ 12 , 13 , 14 , 15 ].…”

Silicon Photoanode Modified with Work‐function‐tuned Ni@FeyNi1−y(OH)2 Core‐Shell Particles for Water Oxidation

“…Indeed, binding energies at 724.7 and 711.2 eV were attributed to Fe 2p 1/2 and Fe2p 3/2 for Fe 3+ in typical Ni II y Fe III 1− y (OH) 2 hydroxide (Figure 2b) [33] . As shown in Figure 2c, O 1s XPS results confirmed the hydroxyl oxygen in Ni(OH) 2 (531.4 eV), both the hydroxyl oxygen and lattice oxygen in Ni II y Fe III 1− y (OH) 2 (531.1 eV for hydroxyl oxygen, 529.7 eV for lattice oxygen) and Fe(OH) 3 (531.4 eV for hydroxyl oxygen, 530 eV for lattice oxygen) [34–36] …”

“…[32] For the n-Si/SiO x /Ni@Ni 0.3 Fe 0.7 (OH) 2 , about 0.5 eV decrease in the binding energy of Ni 2p or Fe 2p compared to the n-Si/SiO x /Ni@Ni(OH) 2 or n-Si/SiO x /Fe(OH) 3 [33] As shown in Figure 2c, O 1s XPS results confirmed the hydroxyl oxygen in Ni(OH) 2 (531.4 eV), both the hydroxyl oxygen and lattice oxygen in Ni II y Fe III 1À y (OH) 2 (531.1 eV for hydroxyl oxygen, 529.7 eV for lattice oxygen) and Fe(OH) 3 (531.4 eV for hydroxyl oxygen, 530 eV for lattice oxygen). [34][35][36] During the CV scanning or PEC test, the Ni y Fe 1À y (OH) 2 is easily oxidized to Ni y Fe 1À y OOH. Indeed, as shown in Figure S3, after a long-period chronoamperometry test on the n-Si/SiO x / Ni 0.3 Fe 0.7 (OH) 2 photoanode, the binding energy at 531.4 eV for OH species in Ni y Fe 1À y (OH) 2 was shifted to 530.6 eV and 531.5 eV for O species in NiOOH/FeOOH, while the binding energies for Ni 2p 3/2 at 856.1 eV and Fe 2p 3/2 at 711.2 eV were assigned to the Ni 3 + and Fe 3 + in Ni y Fe 1À y OOH, [37] verifying the phase transformation to occur.…”

Two-dimensional MOF/MOF derivative arrays on nickel foam as efficient bifunctional coupled oxygen electrodes

“…Notably, R-NCM not only possesses a smaller Rct of 4.31 Ω for OER, but also Rct of 148 Ω for ORR, in contrast to other samples, which contributes to its optimized activity. Therefore, the prominent activity of R-NCM can be derived from synergistic effects of the 2D metal organic framework and its derivative arrays, favorable charge-transfer kinetics, and increased intrinsic active sites [36][37][38].…”