This paper presents a novel method and rationale for utilizing carbonized MOFs for sulphur loading to fabricate cathode structures for lithium–sulphur batteries. Unique carbon materials with differing hierarchical pore structures were synthesized from four types of zinc-containing metal–organic frameworks (MOFs). It is found that cathode materials made from MOFs-derived carbons with higher mesopore (2–50 nm) volumes exhibit increased initial discharge capacities, whereas carbons with higher micropore (<2 nm) volumes lead to cathode materials with better cycle stability.

A novel ultra-lightweight three-dimensional (3-D) cathode system for lithium sulphur (Li–S) batteries has been synthesised by loading sulphur on to an interconnected 3-D network of few-layered graphene (FLG) via a sulphur solution infiltration method. A free-standing FLG monolithic network foam was formed as a negative of a Ni metallic foam template by CVD followed by etching away of Ni. The FLG foam offers excellent electrical conductivity, an appropriate hierarchical pore structure for containing the electro-active sulphur and facilitates rapid electron/ion transport. This cathode system does not require any additional binding agents, conductive additives or a separate metallic current collector thus decreasing the weight of the cathode by typically ∼20–30 wt%. A Li–S battery with the sulphur–FLG foam cathode shows good electrochemical stability and high rate discharge capacity retention for up to 400 discharge/charge cycles at a high current density of 3200 mA g⁻¹. Even after 400 cycles the capacity decay is only ∼0.064% per cycle relative to the early (e.g. the 5th cycle) discharge capacity, while yielding an average columbic efficiency of ∼96.2%. Our results indicate the potential suitability of graphene foam for efficient, ultra-light and high-performance batteries.

Water treatment, the hydrogen evolution reaction, and carbon capture are examples of the potential applications for solar photocatalysis. This has led to significant effort in the search for suitable heterogeneous catalysts. However, materials developed to-date often suffer from disadvantages such as charge recombination, low quantum efficiency, chemical instability, and poor economy of production/operation. These factors have made it difficult for the technology to develop beyond laboratory demonstrations. A potential solution to the problem lies with the appropriate design of the catalyst itself, particularly with respect to particle morphology. This review aims to highlight recent efforts directed towards the development and application of an anisotropic, bi-phasic heterodimer, or “Janus” catalyst. While the topic is in its relative infancy, it has been shown that a Janus morphology can improve catalyst performance by almost an order of magnitude. Hence, a systematic review has been undertaken to highlight and assess recent advances in this field. The review begins with the fundamentals of heterogeneous photocatalysis and proceeds to classify modern catalysts, including Janus particles. This is followed by a detailed description of the relevant studies involving Janus morphology and their demonstrated photocatalytic applications. Finally, an overview of the current challenges and future prospects is discussed along with a summary of the key highlights. It is observed that a Janus morphology can impart several intriguing advantages such as amplification of electric near-field and efficient charge separation. In order to unlock the full potential of Janus photocatalyst, further research in this direction is warranted.