2D-HfS₂as an efficient photocatalyst for water splitting

Abstract

Two dimensional monolayer nanostructures for water splitting solar photocatalyst are drawing more attention due to their extraordinary properties. Using the first principles calculations we have systematically investigate the structural, electronic and vibrational properties of the corresponding HfS 2 monolayer in both phases of hexagonal (1H) and trigonal (1T). The most stable adsorption configurations and adsorption energies are calculated. The adsorption energy of H 2 O on the substrate is 646.53 kJ/mol for 1H-phase and 621.65 kJ/mol for 1T-phase of HfS 2 . It shows that H 2 O molecule has higher interaction with the HfS 2 substrate. The calculated redox potentials of H 2 O splitting are properly astride by the valence and conduction bands suggesting monolayer of 1H and 1T-HfS 2 shows same characteristic as a photocatalyst for water splitting.Further we have also calculated obtained optical band gap for 1H and 1T phases of HfS 2 is 2.60 eV and 3.10 eV, respectively. We have also calculated Raman spectrum signatures of the monolayer 1H and 1T-phase of in -plane vibrational mode of the Hf and S atoms (E 1g ) and the out-of-plane vibrational mode of S atoms (A 1g and A 2u ). Our works suggest a lot more research and attention in this field needed for their practical application as a visible light active photocatalysts.

Efficient charge separation and visible-light response in bilayer HfS2-based van der Waals heterostructures

“…Moreover, the catalytic activity depends on the related work function (F), which represents the minimum quantity of work required to remove an electron from the interior of materials to the vacuum level. Work function is dened by this equation: 14 which means that the catalytic activity of the HfS 2 /h-BN heterostructure is better than that of the HfS 2 /g-C 3 N 4 heterojunction. HfS 2 /h-BN and HfS 2 /g-C 3 N 4 heterostructures are both direct bandgap semiconductors, whose bandgaps have been observed to reduce to 1.78 eV and 1.29 eV, as presented in Table 2.…”

Impact of edge structures on interfacial interactions and efficient visible-light photocatalytic activity of metal–semiconductor hybrid 2D materials

“…1 2D semiconducting materials such as transition metal dichalcogenides (TMDs), metal chalcogenides (e.g., MoS 2 , WS 2 ), hexagonal boron nitrides (h-BNs), and metal oxides have garnered massive interest in experimental studies as well as theoretical studies due to their unique physical and chemical properties. [2][3][4][5][6][7][8] The challenges mentioned above can be easily handled with the band engineering of these semiconductors to develop catalysts with high photocatalysis performance. 9 The possibilities to explore the recent advances in van der Waals (vdW) solids of atomic layers that form vertical quantum heterojunctions with interfaces between different 2D materials.…”

First‐Principles Calculations of Phonons and Thermodynamic Properties of Zr(Hf)S2‐Based Nanotubes

“…The symmetry of MeS 2 (Me = Zr, Hf) nanotubes rolled up from the monolayer (001) with the layer group 72 (P 3m1) is described by line groups of families 4-L(2n) n /m (achiral NTs (n, n)), 8-L(2n) n mc (achiral NTs (n, 0)), and 1-Lq p [19] (chiral NTs (n 1 , n 2 ) at nonzero n 1 and n 2 , n 1 > n 2 ). The corresponding isogonal LCAO [11] PBE0 PW [16] HSE06 (GW) LAPW [27] PBE (GW)…”

“…The methods of synthesis, properties, and applications of 2D TMD are considered in recently published reviews. [4,7,8] The ZrS 2 and HfS 2 nanotubes have been synthesized since the early 2000s. [5,6] Among the other transition metal dichalcogenides, the disulfides of Hf and Zr have attracted a significant attention because of their unique electronic features resulted in numerous applications in photocatalysis and electrochemical intercalation.…”

“…[1][2][3][4] Particularly, it was demonstrated that nanotubes produced from layered transition metal disulfides MoS 2 and WS 2 exhibit a stable, closed, hollow structure. [6,9,10] The theoretical modeling was carried out in references [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] for bulk Zr(Hf) sulfides and their monolayers. [4,7,8] The ZrS 2 and HfS 2 nanotubes have been synthesized since the early 2000s.…”