Vol.:(0123456789) 1 3 Applied Nanoscience (2018) 8:987–999 https://doi.org/10.1007/s13204-018-0772-2 ORIGINAL ARTICLE The suitability of silicon carbide for photocatalytic water oxidation M. Aslam 1  · M. T. Qamar 2  · Ikram Ahmed 3  · Ateeq Ur Rehman 4  · Shahid Ali 5  · I. M. I. Ismail 1,6  · Abdul Hameed 1,7 Received: 8 January 2018 / Accepted: 12 April 2018 / Published online: 18 April 2018 © Springer-Verlag GmbH Germany, part of Springer Nature 2018 Abstract Silicon carbide (SiC), owing to its extraordinary chemical stability and refractory properties, is widely used in the manufac- turing industry. Despite the semiconducting nature and morphology-tuned band gap, its efcacy as photocatalysts has not been thoroughly investigated. The current study reports the synthesis, characterization and the evaluation of the capability of silicon carbide for hydrogen generation from water splitting. The optical characterization of the as-synthesized powder exposed the formation of multi-wavelength absorbing entities in synthetic process. The structural analysis by XRD and the fne microstructure analysis by HRTEM revealed the cubic 3C-SiC (β-SiC) and hexagonal α-polymorphs (2H-SiC and 6H-SiC) as major and minor phases, respectively. The Mott–Schottky analysis verifed the n-type nature of the material with the fat band potential of − 0.7 V. In the electrochemical evaluation, the sharp increase in the peak currents in various potential ranges, under illumination, revealed the plausible potential of the material for the oxidation of water and generation of hydrogen. The generation of hydrogen and oxygen, as a consequence of water splitting in the actual photocatalytic experi- ments, was observed and measured. A signifcant increase in the yield of hydrogen was noticed in the presence of methanol as h + scavenger, whereas a retarding efect was ofered by the Fe 3+ entities that served as e − scavengers. The combined efect of both methanol and Fe 3+ ions in the photocatalytic process was also investigated. Besides hydrogen gas, the other evolved gasses such as methane and carbon monoxide were also measured to estimate the mechanism of the process. Keywords Silicon carbide · Water splitting · Hydrogen generation · h + –e − scavenger Introduction The demand for environment friendly, clean and renew- able energy sources has gained substantial attention with the declining environmental health of the sphere due to the consumption of fossil fuel reserves. Although hydrogen is the most idyllic energy carrier in this regard without releas- ing any toxic ofshoots to solve the global energy issue (Chen et al. 2010; Muradova and Veziroglub 2008), how- ever, currently, the majority of the hydrogen production is mainly extracted from the non-renewable fossil fuels with the addition of carbon dioxide to the environment (Balat and Kırtay 2010; Kothari et al. 2008). Now, the eforts are underway to replace the fossil fuels with the environmental- friendly ingredients for the generation of hydrogen (Çelik and Yıldız 2017; Shankar and Shikha 2017). In the recent years, the splitting of water into hydrogen and oxygen by photocatalysis via powdered photocatalytic water splitting has attracted incredible consideration to conquer clean and carbon-free hydrogen fuel (Frei 2017; Hisatomi and Domen 2017; Chen et al. 2017). The photocatalytic mechanism * Abdul Hameed ahfmuhammad@gmail.com; afmuhammad@kau.edu.sa 1 Centre of Excellence in Environmental Studies (CEES), King Abdulaziz University, Jeddah 21589, Saudi Arabia 2 Department of Chemistry, Forman Christian College (A Chartered University), Ferozepur Road, Lahore 54600, Pakistan 3 Department of Applied Chemistry, Government College University, Faisalabad 38000, Pakistan 4 School of Chemical Engineering, The University of Queensland, Saint Lucia, QLD 4067, Australia 5 Centre of Excellence in Nanotechnology (CENT), King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia 6 Chemistry Department, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia 7 National Centre for Physics, Quaid-e-Azam University, Islamabad 44000, Pakistan