Graphitic carbon nitride nanosheets are extracted, produced via simple liquid-phase exfoliation of a layered bulk material, g-C3N4. The resulting nanosheets, having ≈2 nm thickness and N/C atomic ratio of 1.31, show an optical bandgap of 2.65 eV. The carbon nitride nanosheets are demonstrated to exhibit excellent photocatalytic activity for hydrogen evolution under visible light.

Although lithium ion batteries have gained commercial success owing to their high energy density, they lack suitable electrodes capable of rapid charging and discharging to enable a high power density critical for broad applications. Here, we demonstrate a simple bottom-up approach toward single crystalline vanadium oxide (VO2) ribbons with graphene layers. The unique structure of VO2-graphene ribbons thus provides the right combination of electrode properties and could enable the design of high-power lithium ion batteries. As a consequence, a high reversible capacity and ultrafast charging and discharging capability is achieved with these ribbons as cathodes for lithium storage. A full charge or discharge is capable in 20 s. More remarkably, the resulting electrodes retain more than 90% of the initial capacity after cycling more than 1000 times at an ultrahigh rate of 190C, providing the best reported rate performance for cathodes in lithium ion batteries to date.

Two-dimensional (2D) atomic layers such as graphene, and metal chalcogenides have recently attracted tremendous attention due to their unique properties and potential applications. Unfortunately, in most cases, the freestanding nanosheets easily re-stack due to their van der Waals forces, and lose the advantages of their separated atomic layer state. Here, a bottom-up approach is developed to build three-dimensional (3D) architectures by 2D nanosheets such as MoS 2 and graphene oxide nanosheets as building blocks, the thin nature of which can be well retained. After simply chemical reduction, the resulting 3D MoS 2 -graphene architectures possess high surface area, porous structure, thin walls and high electrical conductivity. Such unique features are favorable for the rapid diffusions of both lithium ions and electrons during lithium storage. As a consequence, MoS 2 -graphene electrodes exhibit high reversible capacity of ≈ 1200 mAh g − 1 , with very good cycling performance. Moreover, such a simple and low-cost assembly protocol can provide a new pathway for the large-scale production of various functional 3D architectures for energy storage and conversions.

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Lithium–sulfur (Li–S) batteries have been hindered by the shuttle effect and sluggish polysulfide conversion kinetics. Here, a P‐doped nickel tellurium electrocatalyst with Te‐vacancies (P⊂NiTe2−x) anchored on maize‐straw carbon (MSC) nanosheets, served as a functional layer (MSC/P⊂NiTe2−x) on the separator of high‐performance Li–S batteries. The P⊂NiTe2−x electrocatalyst enhanced the intrinsic conductivity, strengthened the chemical affinity for polysulfides, and accelerated sulfur redox conversion. The MSC nanosheets enabled NiTe2 nanoparticle dispersion and Li+ diffusion. In situ Raman and ex situ X‐ray absorption spectra confirmed that the MSC/P⊂NiTe2−x restrained the shuttle effect and accelerated the redox conversion. The MSC/P⊂NiTe2−x‐based cell has a cyclability of 637 mAh g‐1 at 4 C over 1800 cycles with a degradation rate of 0.0139% per cycle, high rate performance of 726 mAh g‐1 at 6 C, and a high areal capacity of 8.47 mAh cm‐2 under a sulfur configuration of 10.2 mg cm‐2, and a low electrolyte/sulfur usage ratio of 3.9. This work demonstrates that vacancy‐induced doping of heterogeneous atoms enables durable sulfur electrochemistry and can impact future electrocatalytic designs related to various energy‐storage applications.

It is demonstrated that graphene-based porous silica sheets can serve as an efficient carrier support for PEI via a simple nanocasting technology. The resulting materials possess thin nature, high PEI loading content and high thermal-conductivity. Such features are favorable for the efficient diffusion and adsorption of CO2 as well as the rapid thermal transfer during the CO2 capture process.

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Activated carbon honeycomb supported manganese and cerium oxides (MnO x –CeO2/ACH) catalysts were investigated for selective catalytic reduction (SCR) of NO at low temperatures of 80–200 °C. Compared with ACH supported manganese oxide catalyst (MnO x /ACH), MnO x –CeO2/ACH catalysts show much higher SCR activity and higher selectivity to N2. NO conversion can be improved by the addition of CeO2 from less than 50% to 100% at 80–160 °C. The N2 selectivity of higher than 99.8% is obtained over the Ce(1)Mn/ACH catalyst at 80–200 °C. Results indicate that the addition of CeO2 improves the distribution of MnO x and enhances the oxidation of NO to NO2, producing more absorbed NO3 – on the catalyst surface, which is then reduced into N2 by NH3. These behaviors account for the promoting effect of CeO2 on the SCR activity.