A solder-coated ball (10A) includes a spherical core containing Ni and P; and a solder layer (12) formed to coat the core (11). A solder-coated ball (10B) further includes a Cu plating layer (13) formed between the core (11) and the solder layer (12). A solder-coated ball (10C) further includes an Ni plating layer (14) formed between the Cu plating layer (13) and the solder layer (12).

A solder-coated ball (10A) includes a spherical core containing Ni and P; and a solder layer (12) formed to coat the core (11). A solder-coated ball (10B) further includes a Cu plating layer (13) formed between the core (11) and the solder layer (12). A solder-coated ball (10C) further includes an Ni plating layer (14) formed between the Cu plating layer (13) and the solder layer (12).

Disclosed herein is a catalytic assembly comprising a porous electrically conductive substrate, and a porous metallic composite coating the substrate, where the catalytic assembly has a three dimensional interpenetrating porous structure, where the substrate has a three dimensional interpenetrating porous structure having a first average pore diameter (PD.sub.SUB), and the porous metallic composite is amorphous and has a three dimensional interpenetrating porous structure having a second average pore diameter (PD.sub.PMC), the PD.sub.PMC being sufficiently smaller than the PD.sub.SUB to allow the porous metallic composite to coat substrate surfaces throughout the substrate including surfaces of pores in the substrate. The catalytic assembly may be suitable for use as oxygen evolution reaction (OER) catalysts and hydrogen evolution reaction (HER) catalysts, among others.

Disclosed herein is a catalytic assembly comprising a porous electrically conductive substrate, and a porous metallic composite coating the substrate, where the catalytic assembly has a three dimensional interpenetrating porous structure, where the substrate has a three dimensional interpenetrating porous structure having a first average pore diameter (PD.sub.SUB), and the porous metallic composite is amorphous and has a three dimensional interpenetrating porous structure having a second average pore diameter (PD.sub.PMC), the PD.sub.PMC being sufficiently smaller than the PD.sub.SUB to allow the porous metallic composite to coat substrate surfaces throughout the substrate including surfaces of pores in the substrate. The catalytic assembly may be suitable for use as oxygen evolution reaction (OER) catalysts and hydrogen evolution reaction (HER) catalysts, among others.

Provided is a roughened plated sheet comprising a roughened plated layer having a roughened nickel plated layer and a zinc plated layer famed on at least one surface of a metal substrate in this order from the metal substrate side, wherein a ten-point average roughness Rz.sub.jis of a surface of the roughened plated layer, according to laser microscope measurement, is 3 μm or more.

Provided is a roughened plated sheet comprising a roughened plated layer having a roughened nickel plated layer and a zinc plated layer formed on at least one surface of a metal substrate in this order from the metal substrate side, wherein a ten-point average roughness Rz.sub.jis of a surface of the roughened plated layer, according to laser microscope measurement, is 3 μm or more.

The invention provides a process for preparing an electrode, comprising: electrodeposition of metallic ruthenium/ruthenium oxide (Ru.sup.(0)/RuO.sub.2) coating onto a progressively etched nickel surface; and partial electrochemical oxidation of said metallic ruthenium to ruthenium oxide. The electrode produced and a pseudo-capacitor based on the electrode are also disclosed.

The invention provides a process for preparing an electrode, comprising: electrodeposition of metallic ruthenium/ruthenium oxide (Ru.sup.(0)/RuO.sub.2) coating onto a progressively etched nickel surface; and partial electrochemical oxidation of said metallic ruthenium to ruthenium oxide. The electrode produced and a pseudo-capacitor based on the electrode are also disclosed.

The invention provides a process for preparing an electrode, comprising: electrodeposition of metallic ruthenium/ruthenium oxide (Ru.sup.(0)/RuO.sub.2) coating onto a progressively etched nickel surface; and partial electrochemical oxidation of said metallic ruthenium to ruthenium oxide. The electrode produced and a pseudo-capacitor based on the electrode are also disclosed.

The invention provides a process for preparing an electrode, comprising: electrodeposition of metallic ruthenium/ruthenium oxide (Ru.sup.(0)/RuO.sub.2) coating onto a progressively etched nickel surface; and partial electrochemical oxidation of said metallic ruthenium to ruthenium oxide. The electrode produced and a pseudo-capacitor based on the electrode are also disclosed.