Methylene blue (MB) dye present in industrial wastewater is a well-known carcinogenic source. By utilizing phase pure three dimensional self assembly of magnesium hydroxide nanoparticle (3DSAMHNPs) powders with extremely high surface area (∼342 m2.g–1), very high (∼98%) photocatalytic degradation efficacy for MB dye upon only 60 min direct exposure to sunlight is reported here. The designed mesoporous microstructure of the 3DSAMHNPs chracterized with a narrow pore size distribution range of ∼3-9 nm and an average size of ∼6 nm is achieved at room temperature by a facile, cost effective, simple, wet chemical route. The 3DSAMHNPs powders are characterized by XRD, FESEM, TEM, HRTEM, SAED, EDX, BET surface area, pore size distribution, FTIR, XPS DTA and TGA techniques. Based on the experimental results, a mechanism is proposed for the high MB dye degradation efficacy of 3DSAMHNPs powders developed in the current work. Finally, it is suggested that these 3DSAMHNPs materials may find potential applications in future as reusable photocatalysts for the degradation of MB dye in industrial wastewater
