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The light response range, reusability, and durability of photocatalyst are the key issues for its practical application. To address these problems, the C-doped TiO2/carbon nanofibrous (CTCNF) film with incorporation of C-doped TiO2 nanoparticles into carbon nanofibers was prepared by electrospinning and calcination (pre-oxidation and carbonization). All the obtained CTCNF films exhibited a promising light absorption in ultraviolet-visible region. With optimization of carbonization temperature, the CTCNF film carbonized at 800 °C (CTCNF-800) showed a strongest light absorption. Consequently, the CTCNF-800 possessed a highest photocatalytic degradation efficiency of 94.2% for degradation of rhodamine B. In addition, the CTCNF-800 possessed excellent flexibility and deserved mechanical strength, and hence, the CTCNF-800 could be easily segregated from solution and recycled. Satisfyingly, its degradation efficiency still exceeded 92% after using for six cycles, implying that the CTCNF had excellent reusability and well stability. Besides, the degradation efficiency was over 90% after the CTCNF-800 kept in air without illumination for 1 year, indicating its outstanding durability. The CTCNF film photocatalyst demonstrates tremendous potential in practical application for purification of wastewater. [ABSTRACT FROM AUTHOR]

Herein, considering the great potential of nitrogen-doped hierarchical porous carbons in energy storage and CO 2 capture, we designed a convenient and easily large-scale production strategy for preparing nitrogen-doped hierarchical porous carbon sphere (NHPCS) materials. In this synthesis route, spherical resorcinol-formaldehyde (RF) resins were selected as carbon precursor, and then the ZnCl 2 -impregnated RF resin spheres were carbonized in a NH 3 atmosphere at a temperature range of 600–800 °C. During the one-step heat-treatment process, nitrogen atom could be efficiently incorporated into the carbon skeleton, and the interconnected and hierarchical pore structure with different micro/mesopore proportion could be generated and tuned by adjusting the activating agent ZnCl 2 dosage and carbonization temperature. The resultant nitrogen-doped hierarchical porous carbon sphere materials exhibited a satisfactory charge storage capacity, and the optimal sample of NHPCS-2-8 with a high mesopore proportion obtained at 800 °C with a ZnCl 2 /RF mass ratio of 2:1 presented a specific capacitance of 273.8 F g −1 at a current density of 0.5 A g −1 . More importantly, the assembled NHPCS-2-8-based symmetric capacitor displayed a high energy density of 17.2 Wh kg −1 at a power density of 178.9 W kg −1 within a voltage window of 0 ∼ 1.8 V in 0.5 M Na 2 SO 4 aqueous electrolyte. In addition, the CO 2 capture application of these NHPCS materials was also explored, and the optimal sample of NHPCS-0-8 with a large micropore proportion prepared at 800 °C exhibited an exceptional CO 2 uptake capacity at ambient pressures of up to 4.23 mmol g −1 at 0 °C. [ABSTRACT FROM AUTHOR]

An increasing energy storage property with high rate capability during fast charging at the high current density has been a long-standing challenge for supercapacitors. In this work, a novel nitrogen-enriched graphitized hierarchical porous carbon (NGHPC) was synthesized by a convenient one-step carbonization process from melamine(M)-resorcinol(R)-formaldehyde(F) co-polymeric microspheres using nano γ-Fe 2 O 3 as template, graphitized catalyst precursor and activation promoting agent coupled with ZnCl 2 activation. The nano-sized γ-Fe 2 O 3 was reduced to Fe metal and other Fe-containing species in the carbonization process, and Fe served as catalyst to generate perfectly graphitized carbon skeleton, and other nanoparticles acted as the template of macropores. Meanwhile, CO 2 which generated from the oxidation reactions of CO and γ-Fe 2 O 3 reacted with carbon to bring the in situ CO 2 physical activation, resulting in the promotive tailoring in microporosity. Interestingly, the morphology of the obtaining NGHPC materials could be controlled from spherical aspect to the structure of sphere coated by thin sheet by varying the M/R mass ratio. As supercapacitor electrodes materials, the optimal material achieved an outstanding specific capacitance of 417.5 F g −1 at 0.5 A g −1 in 6 M KOH electrolyte. More importantly, a superb rate capability was also exhibited, and a capacitance of 296.4 F g −1 was still retained at an ultrahigh current density of 100 A g −1 . Besides, the assembled symmetric supercapacitor with the optimal material displayed a high integrated energy density of 33.9 Wh kg −1 at a power density of 809.9 W kg −1 within a voltage range of 0–1.8 V in 0.5 M Na 2 SO 4 natural electrolyte and an approximate 84.8% capacitance retention after consecutive 10,000 cycles at 5 A g −1 . [ABSTRACT FROM AUTHOR]