Attributed to the recent COVID-19 pandemic, panic buying is now a frequent occurrence in many countries, leading to stockouts and supply chain disruptions. Consequently, it has received much attention from academics and the retail industry. The aim of this study is to review, identify, and synthesise the psychological causes of panic buying, which is a relatively new and unexplored area in consumer behaviour research. A systematic review of the related literature is conducted. The review suggests that panic buying is influenced by (1) individuals’ perception of the threat of the health crisis and scarcity of products; (2) fear of the unknown, which is caused by negative emotions and uncertainty; (3) coping behaviour, which views panic buying as a venue to relieve anxiety and regain control over the crisis; and (4) social psychological factors, which account for the influence of the social network of an individual. This study contributes to the literature by consolidating the scarce and scattered research on the causes of panic buying, drawing greater theoretical insights into each cause and also offers some implications for health professionals, policy makers, and retailers on implementing appropriate policies and strategies to manage panic buying. Recommendations for future research are also provided.

A 3D hierarchical structure of MoSe₂/NiSe₂ exhibits superior HER activity because of more active sites and faster transfer of electrons.

Van der Waals heterostructures can preserve the desired features of their individual components and induce new functions due to interlayer coupling. In this work, based on the dispersion-corrected density functional theory and vibrational analysis techniques, the blue phosphorene/graphene (BlueP/G) heterostructure was systematically studied as a potential anode for Li-ion batteries. It was found that the semi-metal characteristics of graphene are well preserved in the BlueP/G heterostructure, endowing it with excellent electrical conductance for fast electron transport. The binding energy of Li in the BlueP/G system is greatly increased due to the interfacial synergistic effect, as compared to pristine BlueP and graphene monolayers. Consequently, the theoretical specific capacity can be up to 626 mA h g⁻¹, even exceeding that of the black phosphorene/G heterostructure (485 mA h g⁻¹). The minimum diffusion barrier of Li on the BlueP/G system is only 0.13 eV, resulting in a room-temperature diffusivity of 2.61 × 10⁻⁵ cm² s⁻¹, which is two orders of magnitude faster than that on graphene. The impact of the vibrational contribution on the ionic diffusion is material-dependent and significant. More importantly, the BlueP/G heterostructure and its charge products display ultrahigh stiffness in the range of 353–422 N m⁻¹ and an extremely small effective volume expansion of 10.89% for the fully charged product, which might alleviate the safety concerns commonly associated with huge volume expansion/contraction upon lithiation. These results demonstrate that the BlueP/G heterostructure could be a promising anode material for high-performance Li-ion batteries due to its excellent conductivity, strong adsorption and fast diffusion of Li, high energy capacity, and ultrahigh mechanical stability.

First-principle calculation based on density functional theory is performed to study the lattice vibration, heat capacity, and thermal conductivity of graphene under strain. Two degenerate optical branches in the phonon dispersion curves split near the G points due to the reduced crystal symmetry, and the frequencies of the optical phonon modes shift down thus inducing more phonon modes at a given temperature. The heat capacity is increased, but the thermal conductivity is reduced because of enhanced Umklapp scattering among more phonons. This phenomenon should be considered when determining the heat management of graphene-based devices.