Retention of anions in cobalt hydroxide with Ni substitution to emphasize the role of anions and cations for high current density in oxygen evolution reactions. Issue 46 (16th November 2020)

• Record Type: Journal Article
• Authors: Shamraiz, Umair; Gul, Rukhsana; Badshah, Amin; Raza, Bareera
• Is Part Of: Dalton transactions. Volume 49:Issue 46(2020)
• Page Start: 16962
• Page End: 16969
• Publication Date: 2020-11-16
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d0dt03200j
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Herein, we report the fabrication of remarkably fine nickel-substituted α-Co(OH)2 sheets using an ingenious co-precipitation method at a lower pH value. Abstract : Herein, we report the fabrication of remarkably fine nickel-substituted α-Co(OH)2 sheets using an ingenious co-precipitation method at a lower pH value. An α-CoNiOOH sheet retains the parent α-Co(OH)2 structure consisting of both tetrahedral (Td) and octahedral (Oh) sites with the retention of interlayer chloride ions, which is in contrast to the previous reports. The as-synthesized α-CoNiOOH sheet exhibits excellent oxygen evolution reactions (OERs) and produces a current of 10 mA cm −2 at an overpotential of merely 190 mV in an alkaline environment. Moreover, the α-CoNiOOH sheet attains an exceptionally high current density of 100 mA cm −2 at a low overpotential of only 270 mV. Additionally, this electrocatalyst possesses a 33 mV dec −1 Tafel slope with higher values of TOF (11 s −1 ) and double-layer capacitance (7.76 mF cm −2 ). This enhancement is attributed partially to the substitution of Ni during the conversion of α-Co(OH)2 to α-CoNiOOH and partially to the exceptionally thin sheets allowing potential octahedral sites for improved oxygen evolution reactions.