Bioactive properties and phytochemical assessment of Bacupari-anão (Garcinia brasiliensis Mart.) leaves native to Rondônia, Brazil

Abstract

Extracts of Garcinia brasiliensis Mart. revealed health promoting biological properties.

A Programmable and Automated Platform for Integrated Synthesis and Evaluation of Water Electrolysis Catalysts

“…The electronic push and pull effects of Co and Fe on Ni were elucidated in detail in our previous work, by performing XPS analysis on the Ni 2p and O 1s spectra and theoretical calculation of the binding energies of adsorbed species. [ 8b ] The consistent shifts of the redox peak position as the Fe/Co concentration changed verified that the platform was able to produce reasonable data unattended, and that it is possible to tune the electrochemical behavior by varying the composition of the trimetallic hydroxide.…”

“…Consistent shifts of the redox peaks in CVs for Ni 2+ were also observed in previous works and they can be attributed to the distinct electron push and pull effects of Co and Fe imposing on Ni which. [ 7,8b ] Fe 3+ tends to pull electrons away from Ni 2+ , and the catalyst as a whole binds the active electrons more tightly therefore it is more difficult to extract electrons from the surface using an external bias, leading to a higher oxidation potential. The effect of Co 2+ is just the opposite.…”

“…The structure of Ni 0.67 Fe 0.33 (OH) x appears to be cellular with thin walls, quite similar to the structures previously reported for the electrodeposited NiFe catalysts. [ 5,8b,10 ] The deposited Ni 0.05 Fe 0.35 Co 0.6 (OH) x catalyst was composed of nodules with a diameter of about 200 nm, resembling typical electrodeposited porous structures. [ 8b ] The phase of the selected catalysts was identified using X‐ray diffraction (XRD).…”

“…[ 5,8b,10 ] The deposited Ni 0.05 Fe 0.35 Co 0.6 (OH) x catalyst was composed of nodules with a diameter of about 200 nm, resembling typical electrodeposited porous structures. [ 8b ] The phase of the selected catalysts was identified using X‐ray diffraction (XRD). As shown in Figure S14, Supporting Information, both diffraction patterns of Ni 0.67 Fe 0.33 (OH) x and Ni 0.05 Fe 0.35 Co 0.6 (OH) x were found to match well with α‐Ni(OH) 2 , suggesting that these catalysts have a layered double hydroxide (LDH) structure.…”

“…[ 7 ] Recently, NiFeCo hydroxides were also explored as a bifunctional catalyst in water splitting since they can also catalyze the hydrogen evolution reaction (HER). [ 8 ] We can easily compare our results to widely available existing data to validate our platform. It has been verified that NiFeCo hydroxides as prepared by electrodeposition are partially crystalline and catalytically active in OER without heat treatment.…”