Malaysian Journal of Analytical Sciences Vol 26 No 3 (2022): 581 - 588

 

 

 

 

PHOTOCATALYTIC HYDROGEN GENERATION FROM WATER BY TiO₂/Co₃O₄ COMPOSITE PHOTOCATALYSIS

 

(Penjanaan Hidrogen Fotokatalitik dari Molekul Air Mengunakan Komposi Fotomangkin TiO₂/Co₃O₄)

 

Siti Nurul Falaein Moridon¹, Dian Anggraini², Khuzaimah Arifin¹*, Lorna Jeffery Minggu¹, Mohammad B. Kassim^1,3

 

¹Fuel Cell Institute,

 Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia

²Department of Chemistry, Faculty of Mathematic and Natural Science,

Universitas Riau,Kampus Binawidya, Km 12.5 Simpang Baru, Pekan baru, Riau, Indonesia,

³Faculty of Science and Technology,

Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia

 

*Corresponding author:  khuzaim@ukm.edu.my

 

 

Received: 28 November 2021; Accepted: 6 March 2022; Published:  27 June 2022

 

 

Abstract

Titanium dioxide (TiO₂) is one of the most studied materials as photocatalyst of water splitting for hydrogen generation. However, TiO₂ has a large band gap of around 3.2 eV, limits its absorption energy to visible light, and the photoexcitation products, such as electron and hole, are recombined rapidly. One method to overcome this problem is by creating a composite heterojunction with other semiconductor materials. In this study, the photocatalytic hydrogen generation of water splitting by TiO₂/Co₃O₄ composite photocatalyst was evaluated. The composite was prepared through hydrothermal synthesis assisted by ball mill crushing, and the powder was annealed at 550 °C. The percentage of Co₃O₄ loading on the TiO₂ varied at 0.5% w/w (TC-05), 1% w/w (TC-1), and 2% w/w (TC-2) to study the suitable amount of Co₃O_4. The surface morphology of the composites was investigated through field emission scanning electron microscopy (FESEM) analyses. Results showed that nanosphere and cubic–shaped morphologies were obtained. For the hydrogen performance analysis, two different conditions of photocatalytic hydrogen generation, which are in pure water and water with addition of 10 vol% of methanol solution as the sacrificial reagent, were measured by using a hydrogen sensor (UNISENSE). TC-1 showed the highest hydrogen production in the pure water, which is 6.75 µmol h^­1 g^­1 compared with others. The addition of 10% methanol enhanced the hydrogen production by three times compared with pure water (20.22 µmol h⁻¹ g⁻¹. The superior heterojunction of TiO₂ and Co₃O₄ performance can be used in practical applications to enhance the photocatalytic properties of TiO_2.

 

Keywords:  cobalt oxide, hydrogen production, PEC, titanium dioxide

 

Abstrak

Titanium dioksida (TiO₂) adalah salah satu bahan yang paling banyak dikaji sebagai fotomangkin pembelahan molekul air untuk penjanaan hidrogen. Walau bagaimanapun, TiO₂ mempunyai jurang jalur yang besar sekitar 3.2 eV, yang mengehadkan tenaga penyerapannya kepada cahaya nampak, dan hasil fotopengujaan, iaitu, elektron dan lubang mengakibatkan bergabung semula dengan cepat. Salah satu cara untuk mengatasi masalah tersebut ialah dengan mencipta gabungan komposit dengan bahan semikonduktor lain. Dalam kajian ini, untuk penjanaan hidrogen bagi pembelahan molekul air fotomangkin gabungan komposit TiO₂/Co₃O₄ telah dinilai. Kaedah sintesis hidroterma dibantu oleh proses penghancuran penggilingan bebola yang digunakan untuk menyediakan komposit berikutan penyepuhlindapan serbuk pada 550 °C. Peratusan pengabungan Co₃O₄ pada TiO₂ telah divariasi pada 0.5% w/w (TC-05), 1% w/w (TC-1), dan 2% w/w (TC-2) untuk mengkaji kadar Co₃O₄ yang sesuai. Morfologi permukaan komposit telah disiasat menggunakan analisis FESEM. Berdasarkan FESEM menunjukkan nanosfera dan berbentuk kubik. Untuk analisis prestasi hidrogen, dua keadaan berbeza penjanaan hidrogen fotokatalitik iaitu dalam air tulen dan air ditambah 10 vol % larutan metanol sebagai reagen, dan telah diukur menggunakan sensor hidrogen (UNISENSE). Hasilnya, TC-1 menunjukkan pengeluaran hidrogen tertinggi dalam air tulen iaitu 6.75 µmol h^-1 g^-1 berbanding yang lain. Penambahan 10% metanol meningkatkan pengeluaran hidrogen 3 kali lebih tinggi berbanding dengan air tulen 20.22 µmol h^-1 g^-1. Gabungan komposit TiO₂ dan Co₃O₄ boleh digunakan dalam aplikasi praktikal meningkatkan sifat fotomangkin TiO₂.

 

Kata kunci:  kobalt oksida, pengeluaran hidrogen, PEC, titanium dioksida

 

 

Graphical Abstract

 

 

References

1.      Acar, C. and Dincer, I. (2020). The potential role of hydrogen as a sustainable transportation fuel to combat global warming. International Journal of Hydrogen Energy, 45(5): 3396-3406.

2.      Rath, B. N., Akram, V., Bal, D. P. and Mahalik, M. K. (2019). Do fossil fuel and renewable energy consumption affect total factor productivity growth? Evidence from cross-country data with policy insights. Energy Policy, 127: 186-199.

3.      Griffiths, S., Sovacool, B. K., Kim, J., Bazilian, M. and Uratani, J. M. (2021). Industrial decarbonization via hydrogen: A critical and systematic review of developments, socio-technical systems and policy options. Energy Research & Social Science, 80: 102208.

4.      Zhao, F., Mu, Z., Hao, H., Liu, Z., He, X., Victor Przesmitzki, S. and Ahmad Amer, A. (2020). Hydrogen fuel cell vehicle development in China: An industry chain perspective. Energy Technology, 8(11): 2000179.

5.      Hosseini, S. E. and Wahid, M. A. (2020). Hydrogen from solar energy, a clean energy carrier from a sustainable source of energy. International Journal of Energy Research, 44(6): 4110-4131.

6.      Mah, A. X. Y., Ho, W. S., Bong, C. P. C., Hassim, M. H., Liew, P. Y., Asli, U. A., ... and Chemmangattuvalappil, N. G. (2019). Review of hydrogen economy in Malaysia and its way forward. International Journal of Hydrogen Energy, 44(12): 5661-5675.

7.      Ahmad, H., Kamarudin, S. K., Minggu, L. J. and Kassim, M. (2015). Hydrogen from photo-catalytic water splitting process: A review. Renewable and Sustainable Energy Reviews, 43: 99-610.

8.      Acar, C. and Dincer, I. (2019). Review and evaluation of hydrogen production options for better environment. Journal of Cleaner Production, 218: 835-849.

9.      Qureshy, A. M., Ahmed, M. and Dincer, I. (2019). Performance assessment study of photo-electro-chemical water-splitting reactor designs for hydrogen production. International Journal of Hydrogen Energy, 44(18): 9237-9247.

10.   Arifin, K., Yunus, R. M., Minggu, L. J. and Kassim, M. B. (2021). Improvement of TiO₂ nanotubes for photoelectrochemical water splitting. International Journal of Hydrogen Energy, 46(7): 4998-5024.

11.   Moridon, S. N. F., Salehmin, M. I., Mohamed, M. A., Arifin, K., Minggu, L. J. and Kassim, M. B. (2019). Cobalt oxide as photocatalyst for water splitting: Temperature-dependent phase structures. International Journal of Hydrogen Energy, 44(47): 25495-25504.

12.   Anggraini, D., Wardani, P. K., Agustina, M., Awaluddin, A.and Arifin, K. (2019). TiO₂/Co₃O₄ Composite as photoanode of photoelectrochemical water splitting. In Journal of Physics: Conference Series, 1351: 012032.

13.   Moridon, S. N. F., Salehmin, M. N. I., Arifin, K., Minggu, L. J. and Kassim, M. B. (2021). Synthesis of cobalt oxide on FTO by hydrothermal method for photoelectrochemical water splitting application. Applied Sciences, 11(7): 3031.

14.   Kumar, S.G. and Rao, K. K. (2017). Comparison of modification strategies towards enhanced charge carrier separation and photocatalytic degradation activity of metal oxide semiconductors (TiO₂, WO₃ and ZnO), Applied Surface Science, 2017: 391124-148.

15.   Alenzi, N., Liao, W. S., Cremer, P. S., Sanchez-Torres, V., Wood, T. K., Ehlig-Economides, C. and Cheng, Z. (2010). Photoelectrochemical hydrogen production from water/methanol decomposition using Ag/TiO₂ nanocomposite thin films. International Journal of Hydrogen Energy, 35(21): 11768-11775.

16.   Wang, L., Tang, G., Liu, S., Dong, H., Liu, Q., Sun, J. and Tang, H. (2022). Interfacial active-site-rich 0D Co₃O₄/1D TiO₂ pn heterojunction for enhanced photocatalytic hydrogen evolution. Chemical Engineering Journal, 428: 131338.