Anchoring black phosphorus quantum dots on molybdenum disulfide nanosheets: a 0D/2D nanohybrid with enhanced visible - and NIR - light photoactivity

摘要

The photocatalytic solar-to-chemical energy conversion by direct utilizing the full spectrum of sunlight is attracting a great deal of current attention. Black phosphorus (BP), a "rising star" of post-graphene two-dimensional (2D) nanomaterial, holds a unique advantage for this purpose on account of its tunable direct-bandgap for broadband absorption. In this work, for the first time, we anchor BP quantum dots (BPQDs) of similar to 4.2 nm in size onto molybdenum disulfide (MoS2) nanosheets of similar to 3 nm in thickness to create 0D/2D nanohybrids with various BP contents (5-20 wt %) via a facile and cost-effective grinding and sonicating approach. The as-prepared BPQDs/MoS2 nanohybrids show enhanced photocatalytic performance towards methylene orange degradation in water under visible - and near - infrared (NIR) light illumination, respectively. Notably, 10 wt% BPQDs/MoS2 nanohybrids with cyclability achieve the highest NIR - driven photoactivity (3 x 10(-2) min(-1)), which is approximately 13 and 27 folds higher than that of individual BPQDs and MoS2, respectively. We demonstrate that the enhanced light absorption, the type - II band alignment, and the interfacial bonding and the spatial charge separation between well-dispersed BPQDs and MoS2 synergetically enhance the photoactivity and photostability. This study may open avenues to create BP-based heterostructures functional in solar-to-chemical energy conversion and beyond.