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• The Ni1Co3@BC hybrid were prepared with ultrasonic stripping and pyrolysis methods. • The B-doped graphitization structure plays additional active sites for OER activity. • Ni1Co3@BC hybrid exhibits the excellent durability, due to internal active sites were protected coming from the carbon layers. Designing and construction of efficient and robust non-noble-metal electrocatalysts for oxygen evolution reaction (OER) is a pivotal approach in water splitting process. This work developed the dual-metal material system of Ni-Co nanoparticles wrapped in B-doped carbon (Ni1Co3@BC) through simple and economical pyrolysis process for nanosheets NiCo metal-organic framework (Ni1Co3-BDC) precursor. The constitution and structure of characterization were characterized by X-ray diffraction, X-ray photoelectron spectroscopy scanning electron microscope and transmission electron microscope, indicating the homogeneous alloy and less metal boride phase and B doped graphitization structure for Ni1Co3@BC. An optimized Ni1Co3@BC exhibited extraordinary OER performance, providing an overpotential as small as 309 mV at a current density of 10 mA cm−2, a low Tafel slope of 62 mV dec−1 and excellent stability in 1.0 M KOH solution, which attributed to the synergistic effect of inner NiCo alloy, NiCo boride nanoparticles and external B doping carbon structure. The formation of B doped carbon layer not only provides additional active sites but also protects inner metal alloys. This work clearly stated the design and synthesis of desired-morphology features catalysts from controlled MOFs for energy conversation and storage. [ABSTRACT FROM AUTHOR]

• Diatomite-supported birnessite–type MnO 2 were synthesized by two methods. • Mnx/DM-AO showed excellent performance for HCHO removal than Mnx/DM-MT. • The crystal defective, surface –OH and lattice oxygen were responsible for the reactivity. • The synergistic effect between diatomite and MnO 2 improved catalytic performance. Diatomite-supported birnessite–type MnO 2 (δ-MnO 2) with different loadings were synthesized through in-situ reduction method by methanol (Mnx/DM-MT) and hydrothermal reduction method by ammonium oxalate (Mnx/DM-AO), respectively. The as-synthesized catalysts were characterized by N 2 adsorption-desorption, X-Ray diffraction, transmission electron microscope, scanning electron microscope, Raman, H 2 -temperature programmed reduction, thermogravimetric, X-ray photoelectron spectroscopy, and in-situ diffuse reflectance infrared Fourier transform spectrometry, and then utilized to catalytic oxidation of formaldehyde at ambient temperature and low temperature (50–250 °C). Compared with the Mnx/DM-MT catalyst, the Mnx/DM-AO catalyst exhibited superior catalytic activity in degrading HCHO at ambient temperature and low temperature. The highly defective structure, abundant hydroxyl groups, rich lattice oxygen and Mn3+ species were responsible for the excellent performance of Mnx/DM-AO. Meanwhile, the Mnx/DM-AO still exhibited good stability obtained from the cyclic testing. In-situ DRIFTS analysis indicated that δ-MnO 2 provided the reactive site, while the diatomite carrier dispersed MnO 2 and also provides a small number of active sites. The synergistic effect between diatomite and δ-MnO 2 benefits the catalytic performance in removal HCHO. The advantages of high activity, low-cost and environment-friendly, suggested that Mn/DM-AO catalyst exhibits promising application foreground in catalytic oxidation of formaldehyde at the temperature from ambient to 250 °C. [ABSTRACT FROM AUTHOR]