VSe ₂ is demonstrated as an appealing candidate for Zn storage, which exhibits excellent electrochemical performance, in particular, rate performance.

K–S battery can be operated at both high and room temperatures (50 and 25 °C) with remarkable electrochemical performance using pyrolyzed selenium disulfide/polyacrylonitrile (SeS₂–CPAN) as the positive electrode and a gel polymer as the electrolyte.

Exploring effective p-type doping in Ga2O3 is crucial for both fundamental science and emerging applications. Recently, N and Zn elements have been shown to exhibit considerable contributions to effective p-type doping in 3D Ga2O3 experimentally and theoretically, whereas the studies of their doping behaviors in 2D Ga2O3 are rare. In this study, we investigate the possibilities of N and Zn elements to achieve effective p-type doping, manifesting in the introduction of shallow acceptor levels typically less than 0.5 eV in 2D Ga2O3 using first-principles calculations with the generalized gradient approximation + U method. The calculated defect formation energies suggest that the N-doped 2D Ga2O3 structures are more easily formed under Ga-rich conditions, while the Zn-doped structures are more readily generated under O-rich conditions. Moreover, the introduced N and Zn atoms preferentially incorporate on the threefold coordinated OII and pyramidally coordinated GaI sites, accompanying with N3− and Zn2+ oxidation states in 2D Ga2O3, respectively. In particular, the electronic structures indicate that the occupied N-2p and semi-occupied Zn-3d orbitals produce shallow hole levels ranging from 0.09 to 0.33 eV, demonstrating that N and Zn atoms can behave as effective p-type dopants in 2D Ga2O3. The magnetic moments for N- and Zn-doped 2D Ga2O3 are 1.00 μB due to the doping of one hole, where the magnetic moments can be mainly attributed to the N atom and the nearest O atoms, respectively. Our work may offer theoretical guidance for the design of p-type 2D Ga2O3 materials and shed light on its potential optoelectronic and magnetic applications.

The magnetic and electronic properties of boron-doped SrTiO₃ have been studied by first-principles calculations. We found that the magnetic ground states of B-doped SrTiO₃ strongly depended on the dopant-dopant separation distance. As the dopant–dopant distance varied, the magnetic ground states of B-doped SrTiO₃ can have nonmagnetic, ferromagnetic or antiferromagnetic alignment. The structure with the smallest dopant-dopant separation exhibited the lowest total energy among all configurations considered and was characterized by dimer pairs due to strong attraction. Ferromagnetic coupling was observed to be stronger when the two adjacent B atoms aligned linearly along the B-Ti-B axis, which could be associated with their local bonding structures. Therefore, the symmetry of the local structure made an important contribution to the generation of a magnetic moment. Our study also demonstrated that the O-Ti-O unit was easier than the Ti-B-Ti unit to deform. The electronic properties of boron-doped SrTiO₃ tended to show semiconducting or insulating features when the dopant–dopant distance was less than 5 Å, which changed to metallic properties when the dopant–dopant distance was beyond 5 Å. Our calculated results indicated that it is possible to manipulate the magnetism and band gap via different dopant–dopant separations.