Graphitic carbon nitride (g-CN) behaving as a layered feature with graphite was indexed as a high-content nitrogen-doping carbon material, attracting increasing attention for application in energy storage devices. However, poor conductivity and resulting serious irreversible capacity loss were pronounced for g-CN material due to its high nitrogen content. In this work, magnesiothermic denitriding technology is demonstrated to reduce the nitrogen content of g-CN (especially graphitic nitrogen) for enhanced lithium storage properties as lithium ion battery anodes. The obtained nitrogen-deficient g-CN (ND-g-CN) exhibits a thinner and more porous structure composed of an abundance of relatively low nitrogen doping wrinkled graphene nanosheets. A highly reversible lithium storage capacity of 2753 mAh/g was obtained after the 300th cycle with an enhanced cycling stability and rate capability. The presented nitrogen-deficient g-CN with outstanding electrochemical performances may unambiguously promote the application of g-CN materials in energy-storage devices.

Novel g-CN/CoO nanocomposite application for photocatalytic H evolution were designed and fabricated for the first time in this work. The structure and morphology of g-CN/CoO were investigated by a wide range of characterization methods. The obtained g-CN/CoO composites exhibited more-efficient utilization of solar energy than pure g-CN did, resulting in higher photocatalytic activity for H evolution. The optimum photoactivity in H evolution under visible-light irradiation for g-CN/CoO composites with a CoO mass content of 0.5 wt % (651.3 μmol h g) was up to 3 times as high as that of pure g-CN (220.16 μmol h g). The remarkably increased photocatalytic performance of g-CN/CoO composites was mainly attributed to the synergistic effect of the junction or interface formed between g-CN and CoO.

The generation of direct white-light emission of the coexisting valence-varied europium-lanthanum aluminate through substitution of cations into the host and its resultant adjustment of the energy transfer have been presented. With respect to La(0.99-x)Sr(x)AlO(3-delta):Eu(0.01) and La(0.994)Al(1-x)O(3-delta):Eu(0.006), and Mn(x), Li(0.012), the green-light emission positioned at 515 nm plays a key role to color mix for white light and can be efficiently tuned by adjusting the transfer of energy and relevant transition emissions between the luminous centers of Eu(2+) and Eu(3+)/Mn(2+), via varying amounts of dopants. Direct white-light emission with optimized values of 86 for the color rendering index and 5091 K for the correlated color temperature has been achieved for lanthanum aluminate by this mixed-valence means.

The combination of alkali metal electrodes and solid-state electrolytes is considered a promising strategy to develop high-energy rechargeable batteries. However, the practical applications of these two components are hindered by the large interfacial resistance and growth of detrimental alkali metal depositions (e.g., dendrites) during cycling originated by the unsatisfactory electrode/solid electrolyte contact. To tackle these issues, we propose a room temperature ultrasound solid welding strategy to improve the contact between Na metal and Na3Zr2Si2PO12 (NZSP) inorganic solid electrolyte. Symmetrical Na|NZSP | Na cells assembled via ultrasonic welding show stable Na plating/stripping behavior at a current density of 0.2 mA cm−2 and a higher critical current density (i.e., 0.6 mA cm−2) and lower interfacial impedance than the symmetric cells assembled without the ultrasonic welding strategy. The beneficial effect of the ultrasound welding is also demonstrated in Na|NZSP | Na3V2(PO4)3 full coin cell configuration where 900 cycles at 0.1 mA cm−2 with a capacity retention of almost 90% can be achieved at room temperature.

Ultrathin graphitic carbon nitride (UGCN) nanosheets with an extended region of visible light response and enhanced surface area were constructed for a significant enhancement in photocatalysis.