Diamond Composite: A “1 + 1 > 2” Strategy to Design and Explore Advanced Functional Materials

Abstract

Diamond composite (DC) refers to a system which consists of diamond (Dia) and other components. Various interactions between diamond and other components exist. The first DC, Dia/beta-silicon carbide (beta-SiC) composite, was grown in 1992 by means of chemical vapor deposition (CVD) technique. Later on, precise control of the distribution, crystallinity, and orientation of both diamond and beta-SiC phases in these composites was sequentially achieved, generating numerous Dia/beta-SiC composites and further leading to their wide applications in diverse fields. Inspired by the activities of Dia/beta-SiC composites, other DCs, produced using different CVD techniques, have been reported, including Dia/carbides, Dia/oxides, Dia/nitrides, Dia/sp(2)-carbon, Dia/metal, Dia/metal alloy, and Dia/organic composites. Meanwhile, these composites possess different micro- and nanostructures. Since DCs fully combine the outstanding properties of diamond with those of other components, their utilization in the mechanical, physical, chemical, and biomedical fields have been extensively explored and tested. This "1 + 1 > 2" strategy is believed to be extremely efficient and useful to design and explore advanced diamond functional materials. The origin of superior enhancement and/or new properties of these DCs using the "1 + 1 > 2" strategy stems from the interface and interactions between individual components as well as their synergistic effects. This Account summarizes the progress and achievements of DCs in our group. Their typical synthesis methods, namely, dry and wet ones, are first overviewed. The dry methods are conducted in the gas phase(s), covering high-pressure high-temperature (HPHT) method, CVD method, and physical vapor deposition (PVD). While the wet methods mainly include electrochemical deposition and hydrothermal processes. The mechanical, and physical features of different Dia/beta-SiC DCs are then detailed. Some application examples of these Dia/beta-SiC DCs are highlighted. In the second part of this Account, synthesis and applications of other DCs, especially those with photo/electrochemical features, are illustrated, for example, the electrocatalysis of Dia/graphite composites toward oxygen reduction/evolution reactions (ORR/OER) and further the construction of flexible zinc-air batteries, the use of Dia/oxides (carbide) composites for the construction of battery-like supercapacitors, the employment of Dia/TiO2 composites for photoelectrochemical degradation of environmental pollutants, and the application of Dia/metal composites for electrochemical sensing. This Account finishes with the future prospects of DCs, encompassing their meticulous conceptualization and synthesis, as well as their multifarious applications across diverse domains.