This review summarizes systematically the growth, properties, and electrochemical applications of conductive diamond.

Syngas, a CO and H₂ mixture mostly generated from non-renewable fossil fuels, is an essential feedstock for production of liquid fuels. Electrochemical reduction of CO₂ and H⁺/H₂O is an alternative renewable route to produce syngas. Here we introduce the concept of coupling a hydrogen evolution reaction (HER) catalyst with a CDots/C₃N₄ composite (a CO₂ reduction catalyst) to achieve a cheap, stable, selective and efficient route for tunable syngas production. Co₃O₄, MoS₂, Au and Pt serve as the HER component. The Co₃O₄-CDots-C₃N₄ electrocatalyst is found to be the most efficient among the combinations studied. The H₂/CO ratio of the produced syngas is tunable from 0.07:1 to 4:1 by controlling the potential. This catalyst is highly stable for syngas generation (over 100 h) with no other products besides CO and H₂. Insight into the mechanisms balancing between CO₂ reduction and H₂ evolution when applying the HER-CDots-C₃N₄ catalyst concept is provided.

High performance ultraviolet (UV) photodetectors based on semiconducting nanowires are expected to have extensive applications in UV-ray detection, optical communication and environmental monitoring. In this work, GaN nanowire photodetectors have been fabricated and giant UV photoresponse has been achieved with Pt nanoparticle (NP) modification. The peak responsivity and external quantum efficiency (EQE) of the GaN nanowire UV photodetector were increased from 773 to 6.39 × 10⁴ A W⁻¹ and from 2.71 × 10⁵% to 2.24 × 10⁷%, respectively, and the response time and sensitivity were improved greatly after Pt NP decoration on the GaN nanowire surface. Moreover, the Pt–GaN nanowire photodetector still presents its spectrum selectivity in the UV region. Our results reveal that Pt nanoparticles play a key role in enhancing the photodetection performance of the nanodevice due to the strong absorption and scattering of incident light induced by localized surface plasmon resonance (LSPR) and the improvement of interfacial charge separation owing to the special device configuration. These findings offer an efficient avenue toward the performance enhancement of GaN nanowire and related optoelectronic devices or systems.