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A novel porous sintered Ni metal as the matrix for supporting MoS 2 /Ni 3 S 2 hierarchical nanorods is successfully prepared by powder metallurgy and hydrothermal sulfurization. The porous sintered Ni-metal matrix supported with the MoS 2 /Ni 3 S 2 displays more advantages over Ni foam, including enhanced catalytic activity and stability, as well as the sufficient mechanical properties, which can be beneficial for the industrial service. [Display omitted] • The porous Ni metal substrate is fabricated via powder metallurgy. • The catalyst of MoS 2 /Ni 3 S 2 with hierarchical structures is confirmed. • The catalytic activity, conductivity and stability for HER are improved. • The self-supporting electrode exhibits sufficient mechanical properties. • NiO controlled by the annealing temperature determines the morphology. For the self-supporting catalysts of Hydrogen evolution reaction (HER), the rational design and fabrication of substrate with porous structure and sufficient mechanical strength are critical to promoting the industrial HER application. In this work, a novel porous sintered Ni metal as the matrix for supporting catalysts was successfully prepared by powder metallurgy, and a self-supporting electrode for HER was fabricated via a simple sulfurization process on this sintered Ni metal matrix. For instance, MoS 2 /Ni 3 S 2 nanorods (NRs) were vertically grown on the as-sintered porous Ni matrix, and the morphology of the sintered Ni matrix significantly affected the growth of MoS 2 /Ni 3 S 2 NRs. The NRs@Sintered Ni electrode shows a low overpotential of η10 = 56 mV and Tafel slope of 82 mV dec−1. Compared with NRs@Ni foam, the NRs@Sintered Ni exhibits superior stability, where no exfoliation and cracks are observed on the surface of the electrode after 5000 CV cycles. Ultra-high stability and long-term durability are obtained over 100 h even at high potentials of 200 and 300 mV. Moreover, the tensile strength of the as-obtained electrode based on the sintered Ni manifests nearly 260 times higher than that of NRs@Ni foam, evidencing an excellent mechanical property. This work provides an idea for the preparation of self-supporting metal-based catalytic electrodes in large-scale hydrogen production. [ABSTRACT FROM AUTHOR]

Based on the synergy between MoP and N-doped carbon, MoP nanoparticles encapsulated in N-doped carbon hollow spheres were synthesized using inorganic-organic hybrids as precursors, which shows an excellent stability and activity with an overpotential 96 mV at 10 mA cm−2 and a small Tafel slope of 53 mV dec−1 in alkaline solution. [Display omitted] • A template-free approach was developed to fabricate MoP@NC hollow microsphere. • Inorganic-organic hybrids were used as precursors. • Remarkable electrocatalytic hydrogen evolution performance could be achieved. • The synergy between MoP and the pyridinic N could optimize the electronic structure. Encapsulating transition metal phosphides into nitrogen-doped carbon (NC) materials is an effective strategy to enhance the electrocatalytic performance. Herein, we develop a novel template-free approach to rationally fabricate molybdenum phosphide (MoP) nanoparticles encapsulated in N-doped carbon (MoP@NC) hollow microspheres for alkaline hydrogen evolution reaction (HER) by employing inorganic-organic hybrids as precursors, in which phosphorus source of the MoP@NC derives from tetra (hydroxymethyl) phosphorus chloride for the first time. The optimized MoP@NC sample shows a low overpotential of 96 mV at 10 mA cm−2, a small Tafel slope of 53 mV dec−1, and excellent stability. The enhanced HER performance is mainly attributed to the integrated effects of a distinctive hollow structure, high pyridinic N-doping level, and the extremely intimate synergy between MoP and NC. Theoretical calculations indicate that the active sites of the catalyst are mainly located at Mo atoms adjacent to the pyridinic N-doped carbon layer (pyridinic-N-MoP); the synergistic interaction between MoP and pyridinic N (rather than pyrrolic or graphitic N) atoms can lower the d band center of Mo, weaken the Mo-H ads bond and thereby enhance HER performance. In addition, the pyridinic N atoms at the interactive sites play a key role in adsorbing H 2 O and preventing the adsorption of OH*, resulting in accelerating the water splitting. This work provides a new method to rationally synthesize high-efficient and stable MoP-based hollow sphere electrocatalysts for alkaline HER through designing inorganic-organic hybrid precursors. [ABSTRACT FROM AUTHOR]

Novel hollow carbon nitride microspheres were fabricated and employed for the efficient photocatalytic degradation of p-hydroxybenonic and hydrogen evolution. • Hollow carbon nitride microspheres (HCNMS) were designed and synthesized. • OH-HCNMS exhibited enhanced hydrogen evolution than pristine C 3 N 4 at 420 nm. • HCNMS exhibited 4.3 times faster degradation of organics than pristine C 3 N 4. • The modified LUMO orbital configuration was favorable for electron-hole separation. Photocatalysis has attracted extensive interests because of the potential applications in remedying emerging contaminants and easing ever-increasing energy crisis. Towards practical applications of photocatalysis, exploring competing semiconductor materials is a critical challenge. Herein, hollow carbon nitride microspheres (HCNMS) were synthesized via a template-free hydrothermal approach, in which OH groups (OH-HCNMS) were used for further tuning the surface features. Their properties were thoroughly investigated by a number of advanced characterization methods. The as-prepared HCNMS achieved an impressive p-hydroxybenzoic acid (HBA) degradation rate of 0.013 min−1, which was 4.3 times higher than pristine carbon nitride (C 3 N 4), even higher than some heterostructured or noble metal modified C 3 N 4. The enhanced photooxidation activity of HCNMS was achieved because of the optimized band structure and the deepened valence band edge, as unveiled by both experimental and density functional theory (DFT) calculation results. In addition, OH-HCNMS exhibited an apparent quantum efficiency (AQE) of 3.7% at 420 nm. The improved hydrogen efficiency of OH-HCNMS was ascribed to the surface functionalized OH groups, which react with holes, and release more electrons to participate the water splitting, as well as the modified orbital configuration which facilitates the faster charge carrier transfer. [ABSTRACT FROM AUTHOR]