A hollow fiber (HF) membrane incorporating molybdenum trioxide (MoO.sub.3) nanoparticles. The membrane may be composed of PPSU hollow fibers that are coated or encrusted with MoO.sub.3 nanoparticles and can be made by dry-wet spinning. The hollow fiber membranes containing MoO.sub.3 nanoparticles remove lead, cadmium or other heave metals from waste water and are resistant to attachment of bacteria and fouling.

Provided are a method of synthesizing molybdenum dioxide (MoO.sub.2) directly onto a metal substrate to form a coating on the surface of the substrate, products having a coated metal surface produced by the disclosed method, and their uses to decontaminate water and/or air. The coated metal surface disclosed herein also may be used as a structural component of a Li-ion battery, a supercapacitor, or a sensor for detecting a molecule.

Provided are a method of synthesizing molybdenum dioxide (MoO.sub.2) directly onto a metal substrate to form a coating on the surface of the substrate, products having a coated metal surface produced by the disclosed method, and their uses to decontaminate water and/or air. The coated metal surface disclosed herein also may be used as a structural component of a Li-ion battery, a supercapacitor, or a sensor for detecting a molecule.

This disclosure provides a unique approach for the synthesis of non-stoichiometric, mesoporous metal oxides with nano-sized crystalline wall. The as-synthesized mesoporous metal oxide is very active and stable (durability >11 h) electocatalyst in both acidic and alkaline conditions. The intrinsic mesoporous metal oxide serves as an electrocatalyst without the assistant of carbon materials, noble metals, or other materials, which are widely used in previously developed systems. The as-synthesized mesoporous metal oxide has large accessible pores (2-50 nm), which are able to facilitate mass transport and charge transfer. The as-synthesized mesoporous metal oxide requires a low overpotential and is oxygen deficient. Oxygen vacancies and mesoporosity served as key factors for excellent performance.

This disclosure provides a unique approach for the synthesis of non-stoichiometric, mesoporous metal oxides with nano-sized crystalline wall. The as-synthesized mesoporous metal oxide is very active and stable (durability >11 h) electocatalyst in both acidic and alkaline conditions. The intrinsic mesoporous metal oxide serves as an electrocatalyst without the assistant of carbon materials, noble metals, or other materials, which are widely used in previously developed systems. The as-synthesized mesoporous metal oxide has large accessible pores (2-50 nm), which are able to facilitate mass transport and charge transfer. The as-synthesized mesoporous metal oxide requires a low overpotential and is oxygen deficient. Oxygen vacancies and mesoporosity served as key factors for excellent performance.

The preparation method according to the present disclosure is to easily prepare hexagonal molybdenum oxide (h-MoO.sub.3) having a nanorod shape even in a low temperature precipitation reaction at atmospheric pressure without applying hydrothermal synthesis under high temperature and high pressure conditions. The hexagonal molybdenum oxide (h-MoO.sub.3) nanorods prepared therefrom can be properly mixed with carbon-based conductive materials such as carbon nanofiber, and thus can be usefully used as an anode material for a pseudocapacitor.

The preparation method according to the present disclosure is to easily prepare hexagonal molybdenum oxide (h-MoO.sub.3) having a nanorod shape even in a low temperature precipitation reaction at atmospheric pressure without applying hydrothermal synthesis under high temperature and high pressure conditions. The hexagonal molybdenum oxide (h-MoO.sub.3) nanorods prepared therefrom can be properly mixed with carbon-based conductive materials such as carbon nanofiber, and thus can be usefully used as an anode material for a pseudocapacitor.

A device and a method for producing high-purity nano molybdenum trioxide are provided. The device comprises a raw material bin (1), a feeding machine (2), a subliming furnace (7), a first vent tube (24), a second vent tube (25), a spraying device (23) and a filtering assembly. The sublimated molybdenum trioxide is cooled with clean and dehumidified air so as to finally obtain the nano molybdenum trioxide, and the recycling mode is reliable, pollution-free and high in efficiency.

A device and a method for producing high-purity nano molybdenum trioxide are provided. The device comprises a raw material bin (1), a feeding machine (2), a subliming furnace (7), a first vent tube (24), a second vent tube (25), a spraying device (23) and a filtering assembly. The sublimated molybdenum trioxide is cooled with clean and dehumidified air so as to finally obtain the nano molybdenum trioxide, and the recycling mode is reliable, pollution-free and high in efficiency.

Provided is a metal oxide production apparatus that implements a flux evaporation method. The production apparatus includes a firing furnace configured to subject a metal compound to firing in the presence of flux, a cooling pipe connected to the firing furnace and configured to convert vaporized flux resulting from the firing into powder, and a recovery means configured to recover powdered flux converted in the cooling pipe. Furthermore, provided is a metal oxide production method comprising a step (1) of subjecting a metal compound to firing in the presence of flux and obtaining a metal oxide and vaporized flux, a step (2) of converting the vaporized flux into powder by cooling the vaporized flux, and a step (3) of recovering powdered flux resulting from the converting.