Efficient utilization of solar energy for clean water is an attractive, renewable, and environment friendly way to solve the long-standing water crisis. For this task, we prepared the long-range vertically aligned graphene sheets membrane (VA-GSM) as the highly efficient solar thermal converter for generation of clean water. The VA-GSM was prepared by the antifreeze-assisted freezing technique we developed, which possessed the run-through channels facilitating the water transport, high light absorption capacity for excellent photothermal transduction, and the extraordinary stability in rigorous conditions. As a result, VA-GSM has achieved average water evaporation rates of 1.62 and 6.25 kg m h under 1 and 4 sun illumination with a superb solar thermal conversion efficiency of up to 86.5% and 94.2%, respectively, better than that of most carbon materials reported previously, which can efficiently produce the clean water from seawater, common wastewater, and even concentrated acid and/or alkali solutions.

To solve the aforementioned problems, emerging graphene agglomerates with crumpled morphologies obtained by the stacking of graphene sheets seem to be promising for increasing the packing density and energy density in energystorage devices. [ 23,24 ] Unfortunately, they usually exhibit a rather low packing density, and consequently a relatively low volumetric capacity. Additionally, the closely stacked graphene agglomerate electrodes generally decrease the ion-accessible surface area and electrolyte ion diffusion, which inevitably compromises its lithium storage capacity. Thus, both a high density and porous structure should be taken into consideration when seeking a strategy for the synthesis of novel carbon-based LIB anodes.Recently, holey graphene, as a new class of graphene derivatives, has attracted extensive attention because of its high intrinsic electrical conductivity, open ion channels, and edge activity useful for applications in electrochemistry-related fi elds. [ 8,25 ] In our previous study, we have demonstrated a lightweight porous graphene foam as advanced electrode material for electrochemical processes (e.g., hydrogen evolution reaction, oxygen reduction reaction, ethanol oxidation reaction, and as electrochemical capacitor). [26][27][28][29][30] Herein, we report a N-doped holey-graphene monolith (NHGM) with a dense microstructure and high density of 1.1 g cm −3 . The holey structure in the individual graphene sheets could not only provide effi cient diffusion channels for Li ions and a highly conductive pathway for electrons, but also provided more edges on the sheet to enhance Li intercalation. [ 31,32 ] NHGM was obtained by conjugating N-containing holey-graphene sheets into a 3D hydrogel, followed by evaporation of the trapped water under vacuum at room temperature and an annealing treatment under Ar atmosphere. This highly compact but porous architecture with heteroatom doping is favorable for ion diffusion, Li ion storage, and maximizing the LIB properties; the NHGM had a volumetric capacity of 1052 mAh cm −3 , which is nearly three times that of commercial graphite anodes (370 mAh cm −3 ), [ 33 ] and exhibited competitive characteristics over the existing Si-based and carbon/sulfur hybrid electrode materials (see Table S1 in the Supporting Information). This makes our graphene-based electrode material an important step toward practical applications.To prepare the N-doped, high-density, holey-graphene monolith (NHGM), we fi rst produced the N-containing holeygraphene hydrogel (NHGH) by a one-pot hydrothermal process with simultaneous etching of nanopores in the graphene sheets and co-assembly of graphene and pyrrole to form a 3D hydrogel. During the hydrothermal process, a controlled amount of H 2 O 2

Herein, we develop a supersensitive pressure sensor based on a fully air-bubbled ultralight graphene block through a simple sparkling strategy. The obtained sparkling graphene block (SGB) exhibits excellent elasticity even at 95% compressive strain and rebounds a steel ball with an ultrafast recovery speed (∼1085 mm s). Particularly, the SGB-based sensor reveals a record pressure sensitivity of 229.8 kPa, much higher than other graphene materials, because of the highly cavity-branched internal structure. Impressively, the pressure sensor can detect the extremely gentle pressures even beyond the real human skin and hence are promising for ultrasensitive sensing applications.

Ultrathin graphitic carbon nitride nanoplatelets (UGCNPs) are synthesized by a facile manner via an efficient and eco-friendly ball milling approach. The obtained UGCNPs are 2-6 nm in size and 0.35-0.7 nm in thickness, with improved specific surface area over that of bulk graphitic carbon nitride. Photochemical experiments show that the UGCNPs are highly active in visible-light water splitting, with a hydrogen evolution rate of 1,365 μmol·h -1 ·g -1 , which is 13.7-fold greater than that of their bulk counterparts. The notable improvement in the hydrogen evolution rate observed with UGCNPs under visible light is due to the synergistic effects derived from the increased specific surface area, reduced thickness, and a negative shift in the conduction band concomitant with the exfoliation of bulk graphitic carbon nitride into UGCNPs. In addition to metalfree visible-light-driven photocatalytic hydrogen production, the UGCNPs find attractive applications in biomedical imaging and optoelectronics because of their superior luminescence characteristics.

The promising complex structures of graphene nanocapsules with in-situ formed graphene sheets (GC-Gs) have been generated by partially peeling the multiwalled graphene capsules (MWGCs) with a small size of ca. 15 nm. The abundant edges and defects on the in-situ induced graphene sheets and capsule walls largely favored the lithiation/de-lithiation reaction and resulted in a high Li-ion storage level. Since the surface area loss of GC-Gs during stacking and aggregation is generally avoided due to the branched structures and the active doping atoms (N, S) can be intercalated into the carbon lattices during sample preparation, the unique GC-Gs possess an excellent reversible capacity of 1373 mAh g −1 at 0.5 A g −1 as anode material in lithium-ion batteries. This value is more than three times that of the theoretical capacity of state-of-the-art graphite counterpart, and higher than those of most carbon materials reported to date and even the composites of metal, alloys with carbon materials.