Depot Institutionnel de l'UMBB >
Publications Scientifiques >
Publications Internationales >
Veuillez utiliser cette adresse pour citer ce document :
http://dlibrary.univ-boumerdes.dz:8080/handle/123456789/10300
|
Titre: | Photoelectrochemical characterization of nano-crednerite AgMnO2 synthesized by Auto-Ignition : a novel Pphotocatalyst for H2 evolution |
Auteur(s): | Koriche, N. Brahimi, R. Bellal, B. Trari, M. |
Mots-clés: | Auto-ignition Crednerite AgMnO2 Hydrogen P-type conductivity Visible light |
Date de publication: | 2022 |
Editeur: | Springer |
Collection/Numéro: | Russian Journal of Electrochemistry/ Vol.58, N°7 (2022);pp. 634-642 |
Résumé: | AgMnO2 nanocrystallites (31 nm) were prepared by sol-gel auto-ignition at 400°C in air. The crednerite characterized by X-ray diffraction (XRD) showed a single phase, crystallizing in a monoclinic unit cell (SG: C2/m). The refinement was made by isotypy with CuMnO2. The oxide is a narrow band-gap semiconductor with an indirect transition at 1.43 eV. The electrical conduction occurs predominantly by small polaron hopping between mixed valences Ag2+/+ in the (a, b) planes with an activation energy of 0.35 eV. The density of holes (NA = 2 × 1015 cm–3) and their mobility (μh = 0.8 × 10–4 m–2 V–1 s–1) indicate a conduction being thermally activated. The oxygen insertion in the layered crystal lattice induces p-type conductivity, a fact confirmed by the electrochemical measurements. The flat band potential (Efb = –0.04 V) indicates a cationic character of both valence and conduction bands deriving mostly from Ag+ 4d-orbital. The electrochemical impedance spectroscopy shows the predominance of the bulk contribution followed by diffusion of O2– species. The energetic band diagram of AgMnO2 established from the photoelectrochemical study, predicts a spontaneous hydrogen formation; a rate evolution of 39 µmol g–1 min–1 and a power conversion of 0.37% were obtained under visible light irradiation (27 mW cm–2) |
URI/URL: | https://link.springer.com/article/10.1134/S1023193522070072 DOI 10.1134/S1023193522070072 http://dlibrary.univ-boumerdes.dz:8080/handle/123456789/10300 |
ISSN: | 10231935 |
Collection(s) : | Publications Internationales
|
Fichier(s) constituant ce document :
Il n'y a pas de fichiers associés à ce document.
|
Tous les documents dans DSpace sont protégés par copyright, avec tous droits réservés.
|