Liyanaarachchi U.S., Fernando C.A.N., Foo K.L., Hashim U., Maza M.
Nano-Technology Research Lab, Department of Electronics, Faculty of Applied Sciences, Wayamba University of Sri Lanka, Kuliyapitiya, Sri Lanka; Institute of Nano Electronic Engineering (INEE), University of Malaysia Perlis (UNIMAP), Kangar, Perlis, Malaysia; UNESCO-UNISA Africa Chairin Nano sciences/Nanotechnology, College of Graduate Studies, University of South Africa (UNISA), Pretoria, South Africa; Nano sciences African Network iThemba LABS, National Research Foundation, Old Faure Road, Western Cape Province, South Africa
Liyanaarachchi, U.S., Nano-Technology Research Lab, Department of Electronics, Faculty of Applied Sciences, Wayamba University of Sri Lanka, Kuliyapitiya, Sri Lanka; Fernando, C.A.N., Nano-Technology Research Lab, Department of Electronics, Faculty of Applied Sciences, Wayamba University of Sri Lanka, Kuliyapitiya, Sri Lanka; Foo, K.L., Institute of Nano Electronic Engineering (INEE), University of Malaysia Perlis (UNIMAP), Kangar, Perlis, Malaysia; Hashim, U., Institute of Nano Electronic Engineering (INEE), University of Malaysia Perlis (UNIMAP), Kangar, Perlis, Malaysia; Maza, M., UNESCO-UNISA Africa Chairin Nano sciences/Nanotechnology, College of Graduate Studies, University of South Africa (UNISA), Pretoria, South Africa, Nano sciences African Network iThemba LABS, National Research Foundation, Old Faure Road, Western Cape Province, South Africa
Well cleaned commercially available copper sheets were heated maintaining different temperature profile heating rates for fabricating p-Cu<inf>2</inf>O nano-surfaces. Initially a heating rate of 10 °C min-1 was provided inside the furnace with copper sheets starting from room temperature until the temperature reached, respectively, 300 °C, 400 °C, 450 °C, and 700 °C, then the temperature was kept constant for 30 min, and then cooled down to room temperature. A single phase nano-p-Cu<inf>2</inf>O was found for the 300 °C, 400 °C, and 450 °C temperature profiles, this may be due to maintaining a slow heating rate avoiding the formation of CuO. Samples prepared from 700 °C temperature profile contained both the p-Cu<inf>2</inf>O and CuO phases. Different surface morphology changes were observed from the AFM micrographs for the samples prepared with the different temperature profiles. A photo-current enhancement was found for the photoelectrochemical cell (PEC) with p-Cu<inf>2</inf>O nano-surfaces produced from the 450 °C temperature profile in comparison to that of the samples prepared from the other temperature profiles. Material characterization from XRD, AFM, FTIR spectra, diffuse reflectance spectra, VI characteristics, time development of the photo-current, Mott-Schottky plots, and estimated band positions were presented for discussing the mechanism of the photo-current enhancement and the highest H<inf>2</inf> generation for the 450 °C temperature profile produced p-Cu<inf>2</inf>O PEC. The highest photocurrent (≈ 10 mAcm-2) and H<inf>2</inf> evolution rate (≈ 130×10-4 Moles l-1min-1) was observed in the presence of a 1 M Na<inf>2</inf>SO<inf>4</inf> electrolyte buffered at a pH of 4.9 with a biased voltage -0:4 V vs Ag/AgCl for the nano-surfaces produced from the 450 °C temperature profile, with comparison to the recently reported highest H<inf>2</inf> evolution rate and highest photocurrent studied by Gratzel and co-workers [A. Parachino, V. Laporte, K. Sivula, M. Gratzel, and E. Thimsen, Nature. Mat. 10, 456 (2011)] providing the same experimental conditions that they have maintained in their experimental work. © 2015 THE PHYSICAL SOCIETY OF THE REPUBLIC OF CHINA.