Enhanced water oxidation performances of birnessite and magnetic birnessite nanocomposites by transition metal ion doping

Abstract

Co2+ and Ni2+ doped layered birnessite and birnessite-manganese ferrite core–shell catalysts displayed enhanced chemical stability and performance in chemical and electrochemical water oxidation reactions.

In situ green synthesis of MnFe2O4@EP@Ag nanocomposites using Epilobium parviflorum green tea extract: An efficient magnetically recyclable catalyst for the reduction of hazardous organic dyes

“…Manganese ferrite (MnFe 2 O 4 ) NPs have been studied extensively in many fields involving medicine, drug delivery, and chemical sensing and have offered good potentials in the field of catalysis depending on its being stable, inexpensive, and magnetically recoverable [38][39][40][41][42][43][44]. Despite this interest, no one to the best of our knowledge has studied MnFe 2 O 4 NPs as a core support material for the coating of a plant or a green tea extract for the immobilization of metal nanoparticles to produce an efficient and recoverable catalyst for their potential applications in the related fields so far.…”

The photogeochemical cycle of Mn oxides on the Earth's surface

“…10a,b) (Hocking et al , 2011; Robinson et al , 2013; Lucht and Mendoza-Cortes, 2015; Thenuwara et al , 2015; Yang et al , 2015). Consequently, the photo-oxidation activity of birnessite has drawn increasing attention, especially for water oxidation (Hocking et al , 2011; Wiechen et al , 2012; Thenuwara, et al, 2015; McKendry et al, 2018; Elmacı et al , 2020).

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Opposite Effects of Co and Cu Dopants on the Catalytic Activities of Birnessite MnO2 Catalyst for Low-Temperature Formaldehyde Oxidation

“…7,[11][12] Additionally, dopants can improve the catalytic activity of δ-MnO2 by enhancing its redox properties and lattice oxygen mobility and reactivity through the reduction of charge transfer resistance. [13][14] Due to their similar ionic radii, Cobalt (Co) was shown to effectively incorporate into the octahedra of δ-MnO2 by substituting Mn 4+ leading to the creation oxygen vacancies. 10 Elmaci et al 13 explored various transition metals as dopants for δ-MnO2 and demonstrated that, compared to the pristine δ-MnO2, Co-doped δ-MnO2 exhibited enhanced catalytic activity and chemical stability for water oxidation reaction.…”

“…[13][14] Due to their similar ionic radii, Cobalt (Co) was shown to effectively incorporate into the octahedra of δ-MnO2 by substituting Mn 4+ leading to the creation oxygen vacancies. 10 Elmaci et al 13 explored various transition metals as dopants for δ-MnO2 and demonstrated that, compared to the pristine δ-MnO2, Co-doped δ-MnO2 exhibited enhanced catalytic activity and chemical stability for water oxidation reaction. This is due to the substitution of Mn 4+ by Co 3+ in the octahedral framework of δ-MnO2 leading to an increase in the ration of Mn 3+ /Mn 4+ .…”