BN-Embedded Graphene with a Ubiquitous Gap Opening

The electronic structures of BN-embedded graphene (BNG) were theoretically studied. A nonzero gap was found to exist in BNG regardless of the edge structures (zigzag/armchair) and the symmetries of the superlattice and BN quantum dots (QDs). The size of the gap is mainly determined by the width of the carbon wall between neighboring BN QDs. It is insensitive to the size of BN QDs, and thus obeys a universal scaling law. This significant and stable energy gap renders BNG as a promising way to control the electronic properties of graphene. The comparison with graphene antidot lattices and nanoribbons was also provided

Graphene-Based Standalone Solar Energy Converter for Water Desalination and Purification

Harvesting solar energy for desalination and sewage treatment has been considered as a promising solution to produce clean water. However, state-of-the-art technologies often require optical concentrators and complicated systems with multiple components, leading to poor efficiency and high cost. Here, we demonstrate an extremely simple and standalone solar energy converter consisting of only an as-prepared 3D cross-linked honeycomb graphene foam material without any other supporting components. This simple all-in-one material can act as an ideal solar thermal converter capable of capturing and converting sunlight into heat, which in turn can distill water from various water sources into steam and produce purified water under ambient conditions and low solar flux with very high efficiency. High specific water production rate of 2.6 kg h^–1 m^–2 g^–1 was achieved with near ∼87% under 1 sun intensity and >80% efficiency even under ambient sunlight (<1 sun). This scalable sheet-like material was used to obtain pure drinkable water from both seawater and sewage water under ambient conditions. Our results demonstrate a competent monolithic material platform providing a paradigm change in water purification by using a simple, point of use, reusable, and low-cost solar thermal water purification system for a variety of environmental conditions