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A recycled solvent-based green synthesis strategy for 2D/3D zeolitic imidazolate frameworks (ZIFs) has been developed to produce functional nanoporous carbons (NPCs) with tuneable morphology, graphitization, N-doping and high porosity via direct pyrolysis. These tailored NPCs show superior supercapacitance performance over typical NPC derived from MOFs and chemical activation/template-directed methods. [Display omitted] • Two important aspects of green synthesis and improved supercapacitance are reported. • A green synthesis route for ZIF-8 via recycling mother liquors (RMLs) is developed. • Rod-/sheet-/polyhedral-like 2D/3D microstructures are produced with RMLs. • 2D/3D NPCs deliver excellent capacitance values and device-level performance. Carbonized metal–organic frameworks (MOFs)-based nanoporous carbon materials (NPCs) offer attractive activities in electrochemical energy conversion and storage (EECS) applications; however, there is the need for scalable MOFs production under reduced energy/environmental impact. This study reports a green synthesis route for model zeolitic imidazolate framework (ZIF-8) materials via recycling methanol-based mother liquors (ZIF-RML x) under room temperature stirring and their carbonized materials (CZC-RML x) for high-performance supercapacitors. Series of ZIF-RML x samples produced in four recycles offer rod-/sheet-/polyhedral-like 2D/3D microstructures with tuneable internal and external framework and morphological features. Accordingly, CZC-RML x , obtained by direct pyrolysis, with high microporosity and surface area of 1500 m2 g−1 deliver excellent capacitance values of 200–340 F g−1, compared to typical MOFs-derived or chemically activated/templated NPCs, produced via extended chemical processing. Structure-relevant and comparative performance analysis reveal insights for improved charge storage and carbonization-dependent graphitization, nitrogen-doping and microporosity-controlled capacitance characteristics in the CZC-RML x over typical NPCs in literature. The device-level performance with a long-term durability over 21,000 cycles is demonstrated. The practical potential of CZC-RML x is further evaluated by fabricating solid-state cells and their parallel and series circuit combinations result in overall capacitance and voltage boost to 450 F g−1 and 2.4 V, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • The pH effect of adhesion force of benzene on graphene is quantitatively studied. • The edge effect of adhesion force is confirmed by experiment. • The potential function method is used to reveal the mechanism of pH effect. • The edge effect is explained by the vdW and electrostatic interaction. Graphene materials, as drug carriers, play an important role in the specific drug delivery system. The drug molecules with aromatic structures can be adsorbed on the surface of graphene in vitro through π-π stacking interaction and released directionally at the lesion under special temperature and pH-value environment. This paper proposes a new experimental method and theoretical model for the purpose to study the effect and mechanism of environmental pH and edge of graphene on the adsorption mechanical properties between graphene and benzene. The experimental results based on atomic force microscope show that the acidic environment is more conducive to the adsorption of benzene on the surface of graphene than the alkaline environment. The adsorption performance of benzene at the center of graphene is better than that at the edge. Moreover, based on experimental results, mechanisms of pH effect and edge effect are revealed by potential function theory. The pH effect is influenced by the change of electrostatic interaction in different pH environments. In addition, edge effect is mainly dominated by van der Waals interaction. This study solves the problem of specific influence mechanism of pH on π-π stacking interaction using mechanical means for the first time, and shows that graphene as a drug carrier has strong pH response characteristics and great application potential. [ABSTRACT FROM AUTHOR]

Single-atomic-Co cocatalyst on (040) facet of BiVO 4 photoanode were prepared, presenting enhanced charge separation efficiency and nearly 100 % charge injection efficiency. [Display omitted] • BiVO 4 (040) photoanodes with various exposure degree of (040) facets were fabricated. • Single-atomic-cobalt cocatalyst was in-situ grown on BiVO 4 (040) photoanode. • BiVO 4 (040)/Co SAs-NC presented nearly 100% charge injection efficiency. Monoclinic bismuth vanadate (BiVO 4) shows promising application prospect in photoelectrochemical (PEC) water splitting on account of its relatively ideal band gap to harvest sunlight. However, the poor charge migrate property and sluggish water oxidation kinetics severely limit the PEC performance of BiVO 4 photoelectrodes. In this work, BiVO 4 photoanode with highly exposed (040) facets for superior charge transfer was prepared by a seed assisted hydrothermal method. Moreover, cobalt single atoms stabilized in N-doped carbon nanosheet (Co SAs-NC) was well modified on BiVO 4 (040) (denoted as BiVO 4 (040)/Co SAs-NC) with much improved water oxidation efficiency. The as-prepared BiVO 4 (040)/Co SAs-NC photoanode generated 2.2 times higher photocurrent density than that of pristine BiVO 4 (040) at 1.23 V vs. RHE, and presented nearly 100% charge injection efficiency. The detail kinetic measurements reveal that the modified Co SAs-NC cocatalyst effectively suppresses the carrier recombination and promotes the surface reaction kinetics. This work provides a promising strategy to fabricate composite photoanodes for solar energy conversion based on facet engineering matched with single-atomic-catalyst. [ABSTRACT FROM AUTHOR]