Two -COOH Decorated Anionic Metal-organic Frameworks with Open Cu2+ Sites Afforded Highly C2H2/CO2 and C2H2/CH4 Separation and Removal of Organic Dyes: Two -COOH Decorated Anionic Metal-organic Frameworks with Open Cu2+ Sites Afforded Highly C2H2/CO2 and C2H2/CH4 Separation and Removal of Organic Dyes