There is provided a surface-treated steel sheet (1) comprising: a tin-plated steel sheet (10) obtained by tin-plating a steel sheet (11); a phosphate compound layer (20) containing tin phosphate formed on the tin-plated steel sheet (10); and an aluminum-oxygen compound layer (30) on the phosphate compound layer (20), a main constituent of the aluminum-oxygen compound layer (30) being an aluminum-oxygen compound; wherein, when the 3d.sub.5/2 spectrum of tin in the aluminum-oxygen compound layer (30) is determined using an X-ray photoelectron spectroscopy, the ratio of the integration value of the profile derived from tin oxide to the integration value of the profile derived from tin phosphate (tin oxide/tin phosphate) is 6.9 or more.

The present invention relates to a Z-type heterojunction photoanode film used for the photocathode protection of a reinforcing bar, the preparation method thereof and a method for the corrosion inhibition of mental materials from concrete structures in marine engineering by using the Z-type heterojunction photoanode film used for the photocathode protection of a reinforcing bar. The preparation method includes steps of preparing Fe.sub.2O.sub.3 on the conducting surface of a clean conductive substrate through the hydrothermal process, preparing Fe.sub.2O.sub.3-PANI composite photoanode film by depositing polyaniline on the surface of Fe.sub.2O.sub.3 through the electrochemical synthesis and preparing Ru-Fe.sub.2O.sub.3-PANI composite photoanode film on the surface of the Fe.sub.2O.sub.3-PANI composite photoanode film through the in situ chemical reduction method. The technical solution in the present invention can achieve highly effective photocathode protection of a reinforcing bar from concretes in marine engineering and improve the durability of concrete structures in marine engineering.

The present invention relates to a Z-type heterojunction photoanode film used for the photocathode protection of a reinforcing bar, the preparation method thereof and a method for the corrosion inhibition of mental materials from concrete structures in marine engineering by using the Z-type heterojunction photoanode film used for the photocathode protection of a reinforcing bar. The preparation method includes steps of preparing Fe.sub.2O.sub.3 on the conducting surface of a clean conductive substrate through the hydrothermal process, preparing Fe.sub.2O.sub.3-PANI composite photoanode film by depositing polyaniline on the surface of Fe.sub.2O.sub.3 through the electrochemical synthesis and preparing Ru-Fe.sub.2O.sub.3-PANI composite photoanode film on the surface of the Fe.sub.2O.sub.3-PANI composite photoanode film through the in situ chemical reduction method. The technical solution in the present invention can achieve highly effective photocathode protection of a reinforcing bar from concretes in marine engineering and improve the durability of concrete structures in marine engineering.

Disclosed herein is an electrolyte comprising OH.sup.− and a hydrogen evolution electrocatalyst, an oxygen evolution electrocatalyst, a bifunctional hydrogen/oxygen evolution electrocatalyst, or any combination thereof for use in in situ deposition or utilization.

Disclosed is a method for preparing a carbon material, comprising applying a voltage to an electrically conductive medium to form an electrically conductive path in an oxygen-free environment containing a carbon source and a catalyst to obtain the carbon material, wherein the electrically conductive medium includes a solid substrate or a liquid-phase electrically conductive system; under the condition that the electrically conductive medium is the liquid-phase electrically conductive system, the carbon material is obtained in the liquid-phase electrically conductive system; and under the condition that the electrically conductive medium is the solid substrate, the carbon material is obtained on a surface of the solid substrate.

Disclosed is a method for preparing a carbon material, comprising applying a voltage to an electrically conductive medium to form an electrically conductive path in an oxygen-free environment containing a carbon source and a catalyst to obtain the carbon material, wherein the electrically conductive medium includes a solid substrate or a liquid-phase electrically conductive system; under the condition that the electrically conductive medium is the liquid-phase electrically conductive system, the carbon material is obtained in the liquid-phase electrically conductive system; and under the condition that the electrically conductive medium is the solid substrate, the carbon material is obtained on a surface of the solid substrate.

A coral reef-like nickel phosphide-tungsten oxide nanocomposite is disclosed. The coral reef-like nickel phosphide-tungsten oxide nanocomposite has a structure in which algae-like transition metal-doped nickel phosphide nanosheets are deposited on coral-like tungsten oxide nanostructures grown vertically on a substrate. This structure allows the coral reef-like nickel phosphide-tungsten oxide nanocomposite to have a large surface area, which leads to a significant increase in the number of catalytic active sites, and ensures high conductivity and electrochemical stability of the coral reef-like nickel phosphide-tungsten oxide nanocomposite. Due to these advantages, the coral reef-like nickel phosphide-tungsten oxide nanocomposite has a low overpotential and superior hydrogen evolution reaction or oxygen evolution reaction efficiency when applied to a water splitting catalyst under alkaline conditions. Also disclosed are a method for preparing the coral reef-like nickel phosphide-tungsten oxide nanocomposite and a catalyst for electrochemical water splitting including the coral reef-like nickel phosphide-tungsten oxide nanocomposite.

A coral reef-like nickel phosphide-tungsten oxide nanocomposite is disclosed. The coral reef-like nickel phosphide-tungsten oxide nanocomposite has a structure in which algae-like transition metal-doped nickel phosphide nanosheets are deposited on coral-like tungsten oxide nanostructures grown vertically on a substrate. This structure allows the coral reef-like nickel phosphide-tungsten oxide nanocomposite to have a large surface area, which leads to a significant increase in the number of catalytic active sites, and ensures high conductivity and electrochemical stability of the coral reef-like nickel phosphide-tungsten oxide nanocomposite. Due to these advantages, the coral reef-like nickel phosphide-tungsten oxide nanocomposite has a low overpotential and superior hydrogen evolution reaction or oxygen evolution reaction efficiency when applied to a water splitting catalyst under alkaline conditions. Also disclosed are a method for preparing the coral reef-like nickel phosphide-tungsten oxide nanocomposite and a catalyst for electrochemical water splitting including the coral reef-like nickel phosphide-tungsten oxide nanocomposite.

A surface-treated copper foil including a treating surface, where the root mean square height (Sq) of the treating surface is in a range of 0.20 to 1.50 μm and the texture aspect ratio (Str) of the treating surface is not greater than 0.65. When the surface-treated copper foil is heated at a temperature of 200° C. for 1 hour, the ratio of the integrated intensity of (111) peak to the sum of the integrated intensities of (111) peak, (200) peak, and (220) peak of the treating surface is at least 60%.

The present invention refers to an electroplating bath for electroplating a chromium or chromium alloy layer, the bath comprising trivalent chromium ions, organic carboxylic acid, sulfate ions, sodium conductive ions, and additives in the form of inorganic sulfur compound and boric acid as well as a process using such an electroplating bath.