Vertical stacking of ultrathin two-dimensional materials via weak van der Waals (vdW) interactions is identified as an important technique for tuning the physical properties and designing viable products for nanoelectronics, spintronics, and renewable energy source applications. The geometry, electronic, and photocatalytic properties of vdW heterostructures of GeC and Janus transition metal dichalcogenides $M\mathrm{SSe}$ ($M$ = Mo, W) monolayers are investigated by performing first-principles calculations. Two different possible models of GeC-$M\mathrm{SSe}$ heterostructures are presented with an alternative order of chalcogen atoms at opposite surfaces in $M\mathrm{SSe}$. The most favorable stacking pattern of both models is dynamically and energetically feasible. A direct type-II band alignment is obtained in both models of understudy heterobilayer systems. The spin orbit coupling (SOC) effect causes considerable Rashba spin splitting in both $M\mathrm{SSe}$ monolayers. In particular, a greater Rashba spin polarization is demonstrated in model 1 (GeC-WSSe) than model 2 (GeC-MoSSe) caused by the alternative order of chalcogen atoms and larger SOC effect of heavier W than Mo atoms, which provides a platform for experimental and theoretical understanding of designing two-dimensional spintronic devices. More interestingly, the appropriate band alignments of model 1 with the standard water redox potentials enable its capability to dissociate water into ${\text{H}}^{+}/{\text{H}}_2$ and ${\text{O}}_2/{\text{H}}_2\text{O}$. In contrast to model 1, model 2 can only oxidize water into ${\text{O}}_2/{\text{H}}_2\text{O}$. The simulated design of GeC-$M\mathrm{SSe}$ is predicted for promising use in future electronic, spintronics, and photocatalytic water splitting.

Using first principles calculations, we investigate the structural and electronic properties of 3d transition metal doped SnO.

An efficient microwave-assisted one-step synthetic route toward Mannich bases is developed from 4-hydroxyacetophenone and different secondary amines in quantitative yields, via a regioselective substitution reaction. The reaction takes a short time and is non-catalyzed and reproducible on a gram scale. The environmentally benign methodology provides a novel alternative, to the conventional methodologies, for the synthesis of mono- and disubstituted Mannich bases of 4-hydroxyacetophenone. All compounds were well-characterized by FT-IR, ¹H NMR, ¹³C NMR, and mass spectrometry. The structures of 1-{4-hydroxy-3-[(morpholin-4-yl)methyl]phenyl}ethan-1-one (2a) and 1-{4-hydroxy-3-[(pyrrolidin-1-yl)methyl]phenyl}ethan-1-one (3a) were determined by single crystal X-ray crystallography. Compound 2a and 3a crystallize in monoclinic, P2₁/n, and orthorhombic, Pbca, respectively. The most characteristic features of the molecular structure of 2a is that the morpholine fragment adopts a chair conformation with strong intramolecular hydrogen bonding. Compound 3a exhibits intermolecular hydrogen bonding, too. Furthermore, the computed Hirshfeld surface analysis confirms H-bonds and π–π stack interactions obtained by XRD packing analyses.

The stability and the electronic properties of two dimensional (2D) GaAs/MoSSe Janus interfaces were investigated using first principles density functional theory calculations. The effect of different atomic terminations on the interface stability, electronic properties and charge transfer at the interfaces were analyzed. Metallic states are formed at the stable MoSSe/GaAs interface owing to the synergistic effect of the presence of 2D occupied antibonding states in MoSSe and the band alignment at the interface. The non-symmetric structure of MoSSe Janus material turns out to play a key role to control the electronic properties of the stable Janus interface, which will be crucial deciding factor for practical applications.