Designing Metallic MoO₂ Nanostructures on Rigid Substrates for Electrochemical Water Activation

Abstract

In situ growth of metallic MoO 2 films on fluorinedoped tin oxide (FTO) and MoO 2 powderi ns olution was achieved simultaneously by as imple hydrothermal process employing citric acid as the surfactant. The growth mechanism of MoO 2 nanostructures (NSs) at the heterogeneousi nterface and in homogeneous mediumproceeds in adifferent manner in which seeds grow in ap referred orientation on FTO, whereas they propagate in all directions in solution. The high lattice matching of FTO and MoO 2 favours the film growth whichc ould not be obtainedo no ther conventional substrates. The disc morphologyo fM oO 2 nanostructures was changed to other diversem orphologyb yv arying the synthesis conditions, particularly by the addition of nitric acid. Ac ompetitive effect of nitric acid and citric acid on the structure direction produced various shapes.T he electrochemicalw ater activation studies showt hat hydrogen-an-nealedM oO 2 is an excellent hydrogen evolution reaction (HER) catalyst with good stability.H -MoO 2 film/FTO displays al ow onset overpotential of72 mV with aT afel slope of 84.1 mV dec À1 ,w hereas the powder form exhibits an onset overpotential of 46 mV with aT afel slope of 71.6 mV dec À1 . The large active surface area, exposure of fringe facets of (110) and the lesser electrochemical charge-transferr esistance offered by the hydrogen-annealed MoO 2 NSsp laya major role in the enhanced HERa ctivity.[a] Dr.

Defect-Engineered MoO2 Nanostructures as an Efficient Electrocatalyst for Oxygen Evolution Reaction

“…The first peaks at 530.23 eV in Figure b and 530.01 eV in Figure d are both due to the lattice oxygen (O L ) in the MoO 2 lattice . The second peaks (531.60 and 531.57 eV) deal with the oxygen deficiencies/vacancies (O V ) within the MoO 2 . , The remaining peaks, that is, 532.35 and 532.66 eV, are associated with the OH – bonds. , The contributions of O V to O L and O OH – to O L increase with the annealing time. That may be due to the bonding of more numbers of H atoms with O atoms with time that hence increases the vacancy of oxygen and occupancy of OH – .…”

Plasma‐assisted synthesis and deposition of molybdenum oxide nanoparticles on polyethylene terephthalate for photocatalytic degradation of rhodamine B

“…[58] The peaks that occurred at 709 and 809 cm −1 were related to Mo-O bonds in the nonstoichiometric molybdenum oxide. [59,60] The bands on the IR spectrum of the PET-molybdenum oxide nanoparticle composite are less intense and some peaks are observed to be shifted, for example, peaks at 1,730 and 1,096 cm −1 (Figure 10c). The peaks' shift may indicate the formation of chemical bonds between the molybdenum oxide nanoparticles and the polymer substrate.…”

“…The low-intensity peaks corresponding to the binding energies 231.5 and 234.9 eV are consistent with Mo 3d 5/2 of the Mo 4+ and Mo 3d 3/2 of the Mo 5+ state, respectively, associated with a nonstoichiometric oxide of the MoO x composition. [59,60,66] Thus, the results of XPS analysis show that the surface of the PET contains a mixture of molybdenum oxides (nonstoichiometric molybdenum oxide).…”

Nickel Cobalt Phosphite Nanorods Decorated with Carbon Nanotubes as Bifunctional Electrocatalysts in Alkaline Medium with a High Yield of Hydrogen Peroxide

“…Hence, alternative low cost and earth abundant catalysts based on non‐precious transition metal oxides and hydroxides (Ni(OH) 2 , Co(OH) 2 , MoO 2 , MoO 3, WO 3 , etc.) and dichalcogenides MoS 2 , CoS 2 are explored for electrocatalysis . Recently, transition metal salts of phosphorous oxy acids have gained more attention towards electrocatalytic applications due to their earth abundance, low cost, environmentally benign nature and high efficiency.…”