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NiFe alloy NPs anchored in NGHS wrapped with self-grown NCNTs with a three-dimensional architecture was constructed successfully for ORR/OER bifunctional catalysis.

Tumor hypoxia is a great physiological barrier for tumor treatment. The development of efficient detection and treatment methods for tumor hypoxia has great scientific and clinical significance. In this work, we investigated the potential of magnetotactic bacteria AMB-1 for magnetic resonance imaging (MRI)-guided magnetic hyperthermia treatment of hypoxic tumors. Our investigations reveal that AMB-1 bacteria can selectively migrate to the hypoxic regions of solid tumors due to their anaerobic characteristics, showing active deep tumor penetrability. Moreover, AMB-1 bacteria exhibit high MRI contrast and magnetic heating performances because of the excellent magnetic performance of their magnetosomes.

The resulting SnPi@CoP–Ni5P4/NCF shows an excellent electrocatalytic performance of OER, which is indicated by a low overpotential of 364 mV for transferring j600 and a low activity decay (2.1%) for the pushed j100 for 50 h.

Metal–organic framework (MOF) derivatives are among the most promising catalysts for the hydrogen evolution reaction (HER) for clean hydrogen energy production. Herein, we report the in situ synthesized MOF-derived CoPO hollow polyhedron nanostructures by simultaneous high temperature annealing and Ar–N2 radio frequency plasma treatment in the presence of a P precursor and subsequent oxygen incorporation from open air at lower temperature. The optimum Ar–N2 gas flow rates are used to precisely tune the P/O ratio, cut Co bonds within the MOFs and reconnect Co with P. Consequently, both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performance are enhanced. Meanwhile, the filling of P elements can effectively change the electronic structure around the catalyst to ensure the uniform distribution of catalytically active sites. The resultant CoPO hollow nanocages with large specific surface areas show excellent bifunctional electrocatalytic activity towards both HER and OER with a low overpotential of 105 and 275 mV and a small Tafel slope of 48 and 52 mV dec−1, respectively. Our results open a new avenue for precise plasma-assisted engineering of MOF-derived hybrid hetero-structured electrocatalysts with rich oxygen vacancies and P dopants to simultaneously boost both half reactions in water electrolysis.

Nanostructured trimetallic phosphide electrocatalysts are promising for H2 and O2 evolution reactions (HER/OER) that are actively pursued nowadays to achieve commercial hydrogen production. Herein, a dual-functional Nb-doped NiFe phosphide nanosheet catalyst with a low cost and high stability was successfully prepared on nickel foam (NF) pretreated with dielectric barrier discharge (DBD) plasmas (PNF) operated under ambient conditions. The resulting Ni12P5–Fe2P–NbP layered nanosheets on the PNF show exceptional catalytic performances, evidenced by their low overpotentials for delivering current densities of 100 and 400 mA cm−2 (j100/j400) of only 178 and 265 mV for the HER, and 280 and 330 mV for the OER, as well as the small Tafel slope values of 52 (HER) and 59 (OER) mV dec−1, respectively. The catalyst also exhibits a good electrocatalytic durability and stability during 100 h continuous HER and OER tests at j300. Moreover, the current densities of 10 and 100 mA cm−2 are achieved at low cell voltages of 1.51 and 1.65 V, thus outperforming most of the reported electrocatalysts in two-electrode alkaline water electrolyzers. Numerical simulation analysis shows that the Ni and Nb atoms in the Ni12P5–Fe2P–NbP nanostructures are the key factors responsible for the achieved excellent performance in water electrolysis.

Electrochemical water splitting is one of the most promising ways for clean hydrogen energy production. Along with using earth-abundant, atomically engineered catalysts that are highly active and stable, clean, chemical-waste-free catalyst production—using minimum resources—is a major hurdle toward achieving zero-carbon-emission commercial operations. Herein, we propose a clean way to fabricate NiSe2–CoSe2 on nickel–cobalt foam (NCF) using pure water for the in situ sprouting of NiCo layered double hydroxide (LDH) precursors. The excellent electrocatalytic activity for overall water splitting in alkaline electrolytes is highlighted by the overpotentials of NiSe2–CoSe2/NCF for delivering current densities of 10 and 400 mA cm−2 (j10 and j400, respectively) at only 24 and 257 mV for hydrogen evolution reaction (HER) and 250 and 346 mV for oxygen evolution reaction (OER), as well as the fast reaction kinetics affording small Tafel slope values of 24 (HER) and 48 (OER) mV dec−1, respectively. NiSe2–CoSe2/NCF exhibits excellent electrocatalytic performance and structural stability, evidenced by the unchanged polarization curve after 104 cycles of CV tests and low decay of high current density (j100) after 100 h of HER and OER measurements. Theoretical analysis revealed that the Co atoms dispersed on the heterointerfaces between the NiSe2 and CoSe2 phases act as the electrocatalytic sites.

Developing highly active electrocatalysts with rich oxygen vacancies and precisely distributed metal sites holds exceptional promise for various renewable and sustainable energy technologies. However, the great challenge is to ensure the stability of oxygen vacancies (VO) during the oxygen evolution reaction (OER) process. Herein, we implement an innovative approach to produce a highly active and stable OER electrocatalyst by plasma-enabled Fe doping of Co-based 2D metal–organic framework (MOF) nanosheets, followed by a carbonization process to fabricate unique triangular-shaped “cheese-like” Fe/Co–carbon nanosheets with a mesoporous structure, and densely and evenly distributed reactive centers, and without damaging the frameworks. The O2–Ar radio frequency (RF) plasma ensured two critical effects, namely oxygen vacancy generation, and forming and modifying the oxidation states of the catalytically active metals in the framework leading to high OER performance. It is shown that filling the oxygen vacancies with Fe heteroatoms helps tune the atomic sites of the two metals in the MOFs and achieve a unique heterostructure where electron currents can be directed between metal sites of different oxidation states. Benefiting from the demonstrated unique advantages of our plasma-enabled approach, the optimized Fe1Co3/VO-800 exhibits a significantly enhanced OER performance and long-term stability, evidenced by a low overpotential of 260 mV at 10 mA cm−2 and a small Tafel slope of 53 mV dec−1. This work provides a new effective approach for the development of next-generation electrocatalysts for diverse applications in environmental and energy fields.