1.Photocatalysis
The solar light is the largest renewable energy resource and is the origin of all power sources like wind, sea-wave, hydraulic power, biomass, and ancient fossil fuels. The total amount of solar energy irradiated on the earth per hour is almost equivalent to the total amount of energy consumed by human per year. Thus, the development of innovative technologies for solar energy conversion and storage is important to solve the energy scarcity problem of the World [1],[2]. Moreover, the solar energy can be also used to produce hydrogen from water, and further contribute to a sustainable society [3]; the abundance of sunlight and water are great assets to support the generation of hydrogen [4].
Hydrogen is an excellent and clean energy carrier and may be generated from water, hydrocarbons, and other organic matters [5]. Currently, hydrogen is produced from oil (18%), natural gas (48%), coal (11%) and water electrolysis (4%) globally [6]. The catalytic reforming of CH4, hydrocarbons or biomass is the major source of hydrogen production [7], [8] but it has severe disadvantages. The major disadvantages include poor yield, high cost and challenge to the environment. Contrarily, the production of hydrogen from water using sunlight is potentially inexpensive and pollution free; this can be done using technologies like photocatalytic water splitting [6],[7].
Hydrogen is produced from water by splitting into hydrogen and oxygen using various methods including photo-electrochemical [9], photocatalytic [10], radiolysis [11], photo-biological [12] methods and thermal decomposition [13]. Among these, photocatalytic water splitting is considered as the best one as an efficient, green, inexpensive process with ease of operation.
In our group, photocatalytic water splitting studies are conducted by investigating variety parameters such as preparation method, different precursor and its structure, noble and non-noble metal doping, variety sacrificial agents and different medium molarities. As preparation methods; solid state reaction, sol-gel, hydrothermal and solvothermal methods are utilized for catalyst synthesis. Same the line with literature, generally TiO2 based catalysts are studied for H2 production, different catalyst investigation are also conducted in our laboratory like Ta2O5, or Nb2O5 based ones. For catalyst’s characterization, researchers benefit from available FTIR, UV-VIS, XRD and SEM analyses which are in our laboratory and university.
References
- Ozdemir, P.,“Comparative Study of Hydrogen Evolution Over Perovskites and Other Oxides”, M.S. Thesis, Dept. of Chemical Eng., Bogazici Univ., (2020).
- [6] D. Saadetnejad, R. Yıldırım, Photocatalytic hydrogen production by water splitting over Au/Al-SrTiO3, Int. Jour. of Hydrogen Energy, Vol: 43, pp:1116-1122, (2017).
General references
- [1] Y.Miseki, K. Sayama, Photocatalytic Water Splitting for Solar Hydrogen Production Using the Carbonate Effect and the Z‐Scheme Reaction, Advance Energy Materials, (2018). https://doi.org/10.1002/aenm.20180129.
- [2] O. Morton, Solar energy: A new day dawning?: Silicon Valley sunrise, Nature, Vol:443, pp:19-22, (2006).
- [3] H. Tada, S.I. Naya, M. Fujishima, Water splitting by plasmonic photocatalysts with a gold nanoparticle/cadmium sulfide heteroepitaxial junction: A mini review, Electrochemistry Communications, Vol: 97, pp:22-26, (2018).
- [4] A.A. Basher, I. Ali, Water photo splitting for green hydrogen energy by green nanoparticles, Int. Jour. of Hydrogen Energy, Vol: 44(23), pp:11564-11573, (2019).
- [5] U. Gupta, C.N.R. Rao, Hydrogen generation by water splitting using MoS2 and other transition metal dichalcogenides, Nanomater Energy, Vol:41, pp:49-65, (2017).
- [7] K. Tao, H. Arano, P. Zhang, P. Ai, L. Han, N. Tsubaki, Enhanced hydrogen production from steam reforming of vegetable oil over bimodal ZrO2-SiO2 supported Ni catalyst, Chem. Select, Vol:2, pp:527-532, (2017).
- [8] K. Tao, Y. Zhang, S. Terao, N. Tsubaki, Development of platinum-based bimodal pore catalyst for CO2reforming of CH4, Catal Today, Vol:153, pp:150-155, (2010).
- [9] Y. Bu, J. Ao, A review on photoelectrochemical cathodic protection semiconductor thin films for metals, Green Energ. Environ., Vol:2, pp:331-362, (2017).
- [10] K. Maeda, K. Domen, Photocatalytic water splitting: recent progress and future challenges, J Phys Chem Lett, Vol:1, pp:2655-2661, (2010).
- [11] A. Cecal, A. Paraschivescu, K. Popa, D. Colisnic, G. Timco, L. Singerean, Radiolytic splitting of water molecules in the presence of some supramolecular compounds, J Serb Chem Soc, Vol:68, pp:593-598, (2003).
- [12] I. Akkerman, M. Janssen, J. Rocha, R.H. Wijffels, Photobiological hydrogen production: photochemical efficiency and bioreactor design, Int J Hydrogen Energy, Vol:27, pp:1195-1208, (2002).
- [13] J. Lede, F. Lapicque, J. Villermaux, Production of hydrogen by direct thermal decomposition of water, Int J Hydrogen Energy, Vol:8, pp:675-679, (1983).
