There is a great challenge to employ an electrocatalyst that has high efficiency, is earth-abundant, and is a non-noble metal for oxygen evolution reaction (OER). Herein, we reported a low-cost and highly efficient OER catalyst, Fe-doped NiCoP nanosheet arrays in situ grown on nickel foam (NiCoFeP/NF), which was synthesized via a simple and mild hydrothermal and phosphorization method. In 1 M KOH solution, the as-prepared NiCoFeP/NF produces a larger current density of 200 mA·cm–2 at a low overpotential of 271 mV and exhibits a low Tafel slope of 45 mV·dec–1, which is superior to commercial RuO2. The outstanding OER performance of the as-prepared NiCoFeP/NF can be attributed to the synergetic effects among Fe, Ni, and Co elements, unique nanosheet arrays structure, and the great intrinsic electrocatalytic activity. On the basis of the above factors, the as-prepared NiCoFeP/NF may work as a promising OER electrocatalyst.

Bio-waste Camellia oleifera shells (COS) are converted into porous carbon by a two-step method.

Controllable conversion of biomass to value-added carbon materials is attractive towards a wide variety of potential applications. Herein, hydrothermal treatment and KOH activation are successively employed to treat the cheap and abundant camellia oleifera shell as a new carbon raw material. It is shown that this stepwise activation process allows the production of porous nitrogen-doped carbon with optimized surface chemistry and porous structure compared to the counterparts prepared by a single activation procedure. Benefiting from the modulated porous structure, the as-produced porous nitrogen-doped carbon electrode delivered a high reversible capacity of 1080 mAh g−1 at a current density of 100 mA g−1, which is 3.3 and 5.8 times as high as that of the carbon materials prepared by bare hydrothermal treatment or KOH activation, respectively. Moreover, the optimized surface composition of the porous nitrogen-doped carbon endows it with a highest initial Coulombic efficiency among the three samples, showing great potentials for practical applications. This work is expected to pave a new avenue to upgrade biomass to carbon materials with tunable surface properties and microstructures for target applications.

Support interactions are critical for controlling the density of exposed MoS2 edge sites and the reactivity for HER.

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Polymeric carbon nitride is a fascinating visible-light-response metal-free semiconductor photocatalyst in recent decades. Nevertheless, the photocatalytic H2 efficiency is unsatisfactory due to the insufficient visible-light harvesting capacity and low quantum yields caused by the bulky structure seriously limited its applications. To overcome these defects, in this research, a 3D hierarchical pancake-like porous carbon nitride (PPCN) was successfully fabricated by a facile bottom-up method. The as-prepared photocatalyst exhibit enlarged surface area, enriched reactive sites, improved charge carrier transformation and separation efficiency, and expanded bandgap with a more negative conduction band towardan enhanced reduction ability. All these features synergistically enhanced the photocatalytic H2 evolution efficiency of 3% Pt@PPCN (430 µmol g−1 h−1) under the visible light illumination (λ ≥ 420 nm), which was nine-fold higher than that of 3% Pt@bulk C3N4 (BCN) (45 µmol g−1 h−1). The improved structure and enhanced photoelectric properties were systematically investigated by different characterization techniques. This research may provide an insightful synthesis strategy for polymeric carbon nitride with excellent light-harvesting capacity and enhanced separation of charges toward remarkable photocatalytic H2 for water splitting.

A novel heterojunction photocatalyst by loading CQDs on Co-g-C3N4 was synthesized by simple hydrothermal process successfully. The crystal phase, surface chemical component and optical properties of CQDs/Co-g-C3N4, Co-g-C3N4 and g-C3N4 were analyzed based on characterizations such as XRD, FT-IR, DRS and PL. The effect of CQDs loading ratio on the properties and photocatalytic performance of the composites was investigated in detail. The optimized CQDs/Co-g-C3N4 (mass ratio of CQDs and Co-g-C3N4 was 0.12%) showed wide visible light adsorption within the wavelength of 800 nm. Moreover, it showed an improved RhB photodegradation efficiency which was 40.9% and 68.3% higher than the value of Co-g-C3N4 and g-C3N4, respectively. The higher photocatalytic activity of CQDs/Co-g-C3N4 should be ascribed to the effective separation of photo-induced carriers.