Fabrication of 3D mesoporous networks of assembled CoO nanoparticles for efficient photocatalytic reduction of aqueous Cr(VI)

Cr(VI) remediation from aqueous environment through modified-TiO2-mediated photocatalytic reduction

“…The enhanced photocatalytic performance may be attributed to its accessible pore volume, appropriate band edge positions and specific reactivity of the crystal phase. Photocatalytic reduction of Cr(VI) proceeds with simultaneous formation of molecular oxygen and hydroxyl radicals at the CoO surface [169]. NiO is a p-type semiconductor, which can conveniently be combined with different photocatalysts and the composite photocatalysts exhibit higher activity [170–172].…”

Unravelling the Elusive Antiferromagnetic Order in Wurtzite and Zinc Blende CoO Polymorph Nanoparticles

“…Concerning wurtzite‐CoO, more systematic studies have only recently been carried out. In particular, wurtzite‐CoO has been found to be rather stable in nanoparticle form and has been reported to have appealing catalytic, optical, semiconducting, electrochemical, and biomedical properties, with possible applications in lithium batteries, solar energy conversion, photoacoustic imaging, and water splitting . In addition, this structure has been shown to appear as a strain relief or polarity compensation phase in rock salt‐CoO thin films, as phase separation in Co‐doped ZnO ultrathin films and in passivation CoO shells of Co nanoparticles .…”

Boosting photochemical activity by Ni doping of mesoporous CoO nanoparticle assemblies

“…Mesoporous Co 1−x Ni x O nanoparticle assemblies (MNAs) were prepared following a previously reported procedure with some modifications. 6 For a typical synthesis of mesoporous Co 1−x Ni x O nanoparticle assemblies (MNAs), 0.2 g of block copolymer Pluronic F127 (OH(CH 2 CH 2 O) 100 (CH(CH 3 )CH 2 O) 64 -(CH 2 CH 2 O) 100 H, M n ∼12 000, Sigma-Aldrich) were dissolved in 1.5 mL of tetrahydrofuran (THF, >99%, Sigma-Aldrich) with continuous stirring. To this solution, 0.5 mL of colloidal Co 1−x Ni x O NP solution in DMF was added dropwise and the mixture was stirred at room temperature for 2 h. Then, the resulting mixture was placed in an oven at 40°C and left for 5 days to give a mesostructured Co 1−x Ni x O/polymer composite.…”

“…Generally, the cubic close-packed structure of CoO is thermodynamically more stable than the hexagonal ones but suffers from poor catalytic activity. 6 Catalytic systems of cubic CoO have only recently demonstrated promising activity for CO oxidation and photocatalytic water-splitting reactions. 7 Herein, we report for the first time chemically stable and robust mesoporous networks of Ni-implanted cubic CoO nanoparticles (NPs) that present high photocatalytic activity for Cr(VI) reduction and water oxidation under UV and visible light irradiation.…”