مشخصات پژوهش

Photocatalytic water splitting is the most promising method for hydrogen production using the power of sunlight [1]. The efficiency of photocatalytic water splitting is governed by the performance of photocatalysts, which generate electron-hole pairs by light irradiation and drive the water splitting reactions. It requires semiconductors with the band gap, larger than the thermodynamic potential for water splitting (1.23 eV), and smaller than the upper bound of the visible solar spectrum (~3 eV). Moreover, the band edges of the semiconductor are required to match the water oxidation and reduction potentials [2,3]. Among the various semiconductors, polymer photocatalysts have attracted increasing attention with the potential to reduce the cost and complexity of current photocatalytic systems. Also, photocatalytic activity in the polymer without the need for co-catalysts, which are often precious metals or unstable molecular complexes [4], could be a very important. Recent reports reveal that both linear and cross-linked conjugated polymers are able to produce hydrogen under visible light irradiation without any added co-catalyst, at a much faster rate than commercial graphitic carbon nitride with platinum nano-particles [5]. Nowadays there has been access to many experimental structures of porous polymers that make it easy to design more potent catalyst compounds. Besides using experimental data, computational methods based on density functional theory (DFT) play an important role in modern catalysis development process. Furthermore, DFT calculations are conducted to unveil the reaction mechanism in catalysis. The thermodynamic, kinetic, and engineering challenges associated with this process lead to exploration of photocatalysis systems. In this way, using DFT calculation, we have been studying porous polymers photocatalysts for hydrogen evaluation. From gradient corrected DFT with a “D3” van der Waals model, we calculated the enthalpies and free energies of the rea