A visible light catalyst, its preparation method, a visible light catalyst activated persulfate system and its use. The visible light catalyst includes a carbon material, a transition metal compound and a coating material. The carbon material is conductive carbon material, and the transition metal compound is selected from one or more of transition metal oxides, transition metal sulfides, and acid or salt compounds containing a transition metal. The visible light catalyst has high visible light photocatalytic activity and performance of degrading organic pollutants and activating persulfate which can result in synergistically degrading degradation-resistant organic pollutants.

Disclosed is a method for preparing adrenochrome by catalytic oxidation using nitrogen-doped carbon nanotubes. The method catalyzes dissolved oxygen in an aqueous solution by the nitrogen-doped carbon nanotubes to rapidly oxidize adrenaline, which is completely transformed into adrenochrome. It is a novel preparation process of adrenochrome, which is simple, and has mild reaction conditions, high product purity, an impurity content less than 10.sup.−8%, and low subsequent processing cost, thereby having a great application prospect. The nitrogen-doped carbon tubes after use can be regenerated and recovered, and its reutilization is still able to realize the complete transformation of adrenaline. The high utilization rate of catalytic material conforms to the concept of energy conservation, minimizing the costs.

Provided are multiwalled carbon nanotubes (MWCNTs) decorated with nanospheres of carbon, methods of preparing multiwalled carbon nanotubes (MWCNTs) decorated with nanospheres of carbon, and uses thereof.

Carbon nanofiber doped alumina (Al-CNF) supported MoCo catalysts in hydrodesulfurization (HDS), and/or boron doping, e.g., up to 5 wt % of total catalyst weight, can improve catalytic efficiency. Al-CNF-supported MoCo catalysts, (Al-CNF-MoCo), can reduce the sulfur concentration in fuel, esp. liquid fuel, to below the required limit in a 6 h reaction time. Thus, Al-CNF-MoCo has a higher catalytic activity than Al—MoCo, which may be explained by higher mesoporous surface area and better dispersion of MoCo metals on the AlCNF support relative to alumina support. The BET surface area of Al—MoCo may be 75% less than Al-CNF-MoCo, e.g., 166 vs. 200 m.sup.2/g. SEM images indicate that the catalyst nanoparticles can be evenly distributed on the surface of the CNF. The surface area of the AlMoCoB5% may be 206 m.sup.2/g, which is higher than AlMoCoB0% and AlMoCoB2%, and AlMoCoB5% has the highest HDS activity, removing more than 98% sulfur and below allowed levels.

The disclosure relates to a photocatalytic structure. The photocatalytic structure includes a substrate, a photocatalytic active layer, and a metal layer. The substrate, the photocatalytic active layer, and the metal layer are arranged in succession. The substrate includes a base and a patterned bulge layer on a surface of the base. The patterned bulge layer is a net-like structure comprising a plurality of strip-shaped bulges intersected with each other and a plurality of indents defined by the plurality of strip-shaped bulges. The plurality of strip-shaped bulges is an integrated structure. The photocatalytic active layer is on the surface of the patterned bulge layer. The metal layer includes a plurality of nanoparticles located on the surface of the photocatalytic active layer away from the substrate.

Proposed are a photocatalyst, including titanium dioxide particles including titanium dioxide (TiO.sub.2), a carbon material located on all or part of the surface of the titanium dioxide particles and including at least one selected from the group consisting of graphene, reduced graphene oxide (rGO), and carbon nanotubes (CNTs), and bimetallic nanoparticles supported on the carbon material and including first metal nanoparticles and second metal nanoparticles, and a water treatment method using the same. In the photocatalyst and the water treatment method using the same, the photocatalyst including bimetallic nanoparticles and graphene oxide is prepared, thereby exhibiting high reduction efficiency and high selectivity to nitrogen gas even without the use of an external electron donor.

A bundle of carbon nanotubes (CNT), comprising a plurality of CNT with lengths of at least about 7 microns, wherein the bundle has a diameter of less than about 12 nm.

The mantle peridotite based-activated carbon nanosheet is a catalyst for cathode oxygen reduction of seawater to generate hydrogen when exposed to sunlight (photocatalytic water splitting). The catalyst is placed in the top surface of seawater and when exposed to sunlight begins to generate hydrogen (H.sup.+). The catalyst mantle peridotite based-activated carbon nanosheet and the sunlight combine generate electricity, mix with seawater splits the seawater significantly generates hydrogen (H.sup.+) from the seawater. The hydrogen is collected and stored in the cathode. From the cathode the collected gas is transferred to the hydrogen storage tank.

A method of fabricating a carbon nanotube (“CNT”) array includes providing a substrate with a CNT catalyst disposed on a surface of the substrate, heating the CNT catalyst to an annealing temperature, exposing the CNT catalyst to a CNT precursor for an exposure period to pre-load the CNT catalyst, and exposing the pre-loaded CNT catalyst to a carbon source for a growth period to form the CNT array. The formed CNT array comprises a plurality of CNT bundles that are aligned with one another in an alignment direction. At least one of the plurality of bundles comprises an average structural factor of 1.5 or less along an entirety of the length thereof.

A catalyst structure is provided. The catalyst structure includes a porous carrier and a plurality of layered hydroxides. The porous carrier includes a nitrogen-doped carbon framework, a plurality of metal oxide particles and a plurality of carbon nanotubes. The nitrogen-doped carbon framework has a plurality of pores. The metal oxide particles are uniformly dispersed in the pores of the nitrogen-doped carbon framework. The carbon nanotubes are located on a surface of the nitrogen-doped carbon framework, and one end of each of the carbon nanotubes is connected to the surface of the nitrogen-doped carbon framework. The layered hydroxides are coated on the surface of the nitrogen-doped carbon framework.