Intriguing electronic, optical and photocatalytic performance of BSe, M₂CO₂monolayers and BSe–M₂CO₂(M = Ti, Zr, Hf) van der Waals heterostructures

Abstract

Using density functional theory calculations, we have investigated the electronic band structure, optical and photocatalytic response of BSe, M2CO2 (M = Ti, Zr, Hf) monolayers and their corresponding BSe–M2CO2 (M = Ti, Zr, Hf) van der Waals heterostructures.

Revealing the electronic, optical and photocatalytic properties of PN-M2CO2 (P = Al, Ga; M = Ti, Zr, Hf) heterostructures

“…In the case of the PN (P = Ga, Al) monolayer, the CBM (VBM) lies at the Γ ( K )-point, while for M 2 CO 2 the VBM lies at the Γ -point and the CBM is between the K and M point of the first BZ, consistent with ref. 43 and 69 . The photocatalytic response in Fig.…”

“…2 , shows that Ti 2 CO 2 and Zr 2 CO 2 cross (fail to cross) the valence (conduction) band edge, while both the PN and Hf 2 CO 2 monolayers cross both the conduction and valence band edges (see also Table 1 ), in agreement with ref. 43 . These results show the potential of PN (M = Ga, Al) and M 2 CO 2 (M = Ti, Zr, Hf) monolayers in photocatalytic applications and the authenticity of the present approach to combine these monolayers to form vdWHs for efficient electronic, optoelectronic and photocatalytic applications.…”

“…The emergence of vdWHs in the 2D field offers a new way to combine different monolayers for novel electronic, optoelectronic, and photocatalytic applications. 36,37 Some vdWHs based on MXene, AlN, and GaN like MoS 2 /MXene, 38 TiO 2 /Mxenes, 39 MXene/graphene, 40 TMDCs/MXenes, 41 SiS/MXenes, 42 BSe/MXenes, 43 AlGaN/GaN, 44 MoSe 2 /GaN, 45 AlN/GaN, 46 WS 2 /GaN, 47 ZnO/GaN, 48 graphene/AlN, 49 BP/AlN, 50 and AlN/InSe, 51 have already been fabricated for practical device applications. Electronic structure, optical properties and overall water splitting performance of GaN/Hf 2 CO 2 and AlN/Hf 2 CO 2 vdWHs have been investigated in ref.…”

Computational studies on functionalized Janus MXenes MM′CT2, (M, M′ = Zr, Ti, Hf, M ≠ M′; T = –O, –F, –OH): photoelectronic properties and potential photocatalytic activities

“…The CBM levels ( vs. NHE) of ZrTiCO 2 -I, ZrHfCO 2 -I, ZrHfCO 2 -III, HfTiCO 2 -I, and HfTiCO 2 -III were 0.23, −0.49, 0.66, 0.15, and 0.93 eV, respectively, suggesting that ZrTiCO 2 -I (0.23 eV), ZrHfCO 2 -I (−0.49 eV), and HfTiCO 2 -I (0.15 eV) can reduce heavy metal ions or other reactants, while ZrHfCO 2 -III (0.66 eV) and HfTiCO 2 -III (0.93 eV) are not suitable for photocatalytic reduction reactions, due to their inappropriate CBM level positions. Nevertheless, the band alignment could be effectively modulated through doping, 56 strain and electric field engineering, 57 and van der Waals heterostructures formation 58 to meet the requirements of the photocatalytic process.…”

“…Compared with the excellent oxidation capability of holes, the reduction capabilities of the conduction band electrons were not and HfTiCO 2 -III (0.93 eV) are not suitable for photocatalytic reduction reactions, due to their inappropriate CBM level positions. Nevertheless, the band alignment could be effectively modulated through doping, 56 strain and electric eld engineering, 57 and van der Waals heterostructures formation 58 to meet the requirements of the photocatalytic process.…”