By acting as the trapping centers during change carrier transfer, the oxygen vacancy (VO) plays a critical role in oxide photoelectric devices. Herein, a post-annealing method was introduced to perfect...

In this study, we demonstrate that plasma treatment can be a facile and environmentally friendly approach to perform surface modification of graphitic carbon nitride (g-CN), leading to a remarkable modulation on its photocatalytic activity. The bulk properties of g-CN, including the particle size, structure, composition, and electronic band structures, have no changes after being treated by oxygen or nitrogen plasma; however, its surface composition and specific surface area exhibit remarkable differences corresponding to an oxygen functionalization induced by the plasma post-treatment. The introduced oxygen functional groups play a key role in reducing the recombination rate of the photoexcited charge carries. As a consequence, the oxygen-plasma-treated sample shows a much superior photocatalytic activity, which is about 4.2 times higher than that of the pristine g-CN for the degradation of rhodamine B (RhB) under visible light irradiation, while the activity of nitrogen-plasma-treated sample exhibits a slight decrease. Furthermore, both of the plasma-treated samples are found to possess impressive photocatalytic stabilities. Our results suggest that plasma treatment could be a conventional strategy to perform surface modification of g-CN in forms of both powders and thin films, which holds broad interest not only for developing g-CN-based high-performance photocatalysts but also for constructing photoelectrochemical cells and photoelectronic devices with improved energy conversion efficiencies.

Polymeric graphitic carbon nitride (g-CN) has emerged as a promising metal-free photocatalyst; however, the polymerization process is still poorly understood, and the synthesized g-CN shows a structural complexity, with photocatalytic activities far from being optimized. Herein we present new insight into its polymerization reaction kinetics and develop a quasi-sealed condensation route to properly regulate the distribution of the degree of polymerization (DP) in the synthesized g-CN. The correlation throughout the condensation process, the structure−property relationship, and the photocatalytic performance of g-CN have been discussed in detail. The synthesized g-CN shows a narrower and uniform DP distribution, possesses improved crystallinity, and features a nanoporous texture with fruitful amine groups and better water dispersibility, which promotes the fast chargecarrier transport under aqueous conditions and give rise to substantially enhanced photocatalytic activity. Compared with the conventional counterpart, its visible-light activity is 4.88 times higher for hydrogen production, 7.81 times higher for the degradation of rhodamine B, and 2.47 times higher for the degradation of 4-chlorophenol. We further report that its solar-driven photocatalytic activity is superior to that of the representative Degussa TiO 2 P25 catalyst for scale-up RhB degradation, thus highlighting the great prospects of g-CN-based photocatalysts toward practical applications.

Novel p-i-n self-powered solar-blind UV photodetector based on p-type spiro-MeOTAD (spiro), Ga2O3, and n-type Si is fabricated. The p-type spiro film is spin-coated on the surface of Ga2O3 film deposited...