Afterglow Electrochemiluminescence from Nitrogen-Deficient Graphitic Carbon Nitride.

Almost all current electrochemiluminescent reagents require real-time electrochemical stimulation to emit light. Here, we report a novel electrochemiluminescent reagent, nitrogen-deficient graphitic carbon nitride (CNx), that can emit afterglow electrochemiluminescence (ECL) after cessation of electric excitation. CNx obtained by post-thermal treatment of graphitic carbon nitride (CN) with KSCN has a cyanamide group and a nitrogen vacancy, which created defects to trap electrically injected electrons. The trapped electrons can slowly release and react with coreactants to emit light with longevity. The cathodic afterglow ECL lasts for 70 s after pulsing the CNx nanosheet (CNxNS-1.6)-modified glassy carbon electrode at -1.0 V for 20 s in 2.0 M PBS containing 1 mM K2S2O8. The afterglow ECL mechanism is revealed by investigation of its influencing factors and ECL wavelength. The discovery of afterglow ECL may open a new doorway for new significant applications of the ECL technique and provide a deeper understanding of the structure-property relationships of CN.

Changes in the expression pattern of OsWUS negatively regulate plant stature and panicle development in rice.

WUSCHEL (WUS) and WUSCHEL-RELATED HOMEOBOX (WOX) encode transcription factors and play important roles in regulating the formation and maintenance of shoot and floral meristems. OsWUS have distinct functions in meristem development with slightly tuned expression. However, the mechanisms regulating the specific expression of OsWUS need to be further explored. In this study, an abnormal expression mutant of OsWUS, called Dwarf and aberrant panicle 1 (Dap1) was used. In order to identify the causal gene in Dap1, high-efficiency thermal asymmetric interlaced (hiTAIL)-PCR and co-segregation analysis were performed. We surveyed the growth and yield traits in Dap1 and wild type. Changes in gene expression between Dap1 and wild type were determined by RNA-seq. The Dap1 mutant is due to the T-DNA inserted at 3,628-bp upstream of the translation start codon of OsWUS. Plant height, tiller numbers, panicle length, the number of grains per main panicle, and the number of secondary branches was significantly reduced in the Dap1 mutant. The expression of OsWUS was markedly increased in Dap1 mutant plants compared to the wild type, which might be due to a disruption in the genomic sequence integrity. Simultaneously, the expression levels of gibberellic acid-related genes and genes involved in panicle development were significantly changed in the Dap1 mutant. Our results suggest that OsWUS is a precise regulatory element, its specific spatio-temporal expression pattern is critical for its function, and both loss-of-function and gain-of-function mutations lead to abnormal plant growth.

B, O and N Codoped Biomass-Derived Hierarchical Porous Carbon for High-Performance Electrochemical Energy Storage.

High specific surface area, reasonable pore structure and heteroatom doping are beneficial to enhance charge storage, which all depend on the selection of precursors, activators and reasonable preparation methods. Here, B, O and N codoped biomass-derived hierarchical porous carbon was synthesized by using KCl/ZnCl2 as a combined activator and porogen and H3BO3 as both boron source and porogen. Moreover, the cheap, environmentally friendly and heteroatom-rich laver was used as a precursor, and impregnation and freeze-drying methods were used to make the biological cells of laver have sufficient contact with the activator so that the layer was deeply activated. The as-prepared carbon materials exhibit high surface area (1514.3 m2 g-1), three-dimensional (3D) interconnected hierarchical porous structure and abundant heteroatom doping. The synergistic effects of these properties promote the obtained carbon materials with excellent specific capacitance (382.5 F g-1 at 1 A g-1). The symmetric supercapacitor exhibits a maximum energy density of 29.2 W h kg-1 at a power density of 250 W kg-1 in 1 M Na2SO4, and the maximum energy density can reach to 51.3 W h kg-1 at a power density of 250 W kg-1 in 1 M BMIMBF4/AN. Moreover, the as-prepared carbon materials as anode for lithium-ion batteries possess high reversible capacity of 1497 mA h g-1 at 1 A g-1 and outstanding cycling stability (no decay after 2000 cycles).

FeNb2O6/reduced graphene oxide composites with intercalation pseudo-capacitance enabling ultrahigh energy density for lithium-ion capacitors.

Lithium-ion capacitors (LICs), which combine the characteristics of lithium-ion batteries and supercapacitors, have been well studied recently. Extensive efforts are devoted to developing fast Li+ insertion/deintercalation anode materials to overcome the discrepancy in kinetics between battery-type anodes and capacitive cathodes. Herein, we design a FeNb2O6/reduced graphene oxide (FNO/rGO) hybrid material as a fast-charge anode that provides a solution to the aforementioned issue. The synergetic combination of FeNb2O6, whose unique structure promotes fast electron transport, and highly conductive graphene shortens the Li+ diffusion pathways and enhances structural stability, leading to excellent electrochemical performance of the FNO/rGO anode, including a high capacity (770 mA h g-1 at 0.05 A g-1) and long cycle stability (95.3% capacitance retention after 500 cycles). Furthermore, the FNO/rGO//ACs LIC achieves an ultrahigh energy density of 135.6 W h kg-1 (at 2000 W kg-1) with a wide working potential window from 0.01 to 4 V and remarkable cycling performance (88.5% capacity retention after 5000 cycles at 2 A g-1).