Premium
Adams Method Prepared Metal Oxide Catalysts for Solar‐Driven Water Splitting
Author(s) -
Browne Michelle P.,
O'Rourke Christopher,
Wells Nathan,
Mills Andrew
Publication year - 2018
Publication title -
chemphotochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.13
H-Index - 18
ISSN - 2367-0932
DOI - 10.1002/cptc.201700210
Subject(s) - overpotential , water splitting , electrocatalyst , oxygen evolution , oxide , materials science , inorganic chemistry , non blocking i/o , platinum , metal , catalysis , anode , electrode , chemical engineering , chemistry , electrochemistry , metallurgy , photocatalysis , engineering , biochemistry
The widespread utilisation of solar‐driven water‐splitting devices is hindered by the use of expensive and unstable materials. Herein, we show that highly active earth‐abundant metal oxide oxygen and hydrogen evolution electrocatalysts can be synthesised using the Adams method, in which the metal salts are oxidised in a melt of sodium nitrate. We also demonstrate that such oxides are usually highly crystalline powders with high specific surface areas. Disc electrodes of the Adams method metal oxides, specifically RuO 2 , Mn 2 O 3 , Co 3 O 4 and NiO, are prepared using a recently reported mechanical, solvent‐free method, involving pressing a mixture of the metal oxide and a small amount (5 wt %) of PTFE powder. Each electrode is tested as an electrode for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in 1 m NaOH. In the former role, Mn 2 O 3 appears better than a platinum wire electrode (overpotential at 10 mA cm −2 , η 10 =61 mV compared to 70 mV for Pt). In the OER study, although RuO 2 is the best electrocatalyst (with η 10 =267 mV), Co 3 O 4 is also very effective (with η 10 =330 mV). Using Mn 2 O 3 as the cathode and Co 3 O 4 as the anode, a silicon solar cell is used to photocleave water into H 2 and O 2 .