Through an understanding of the growth mechanism of diluted magnetic semiconductor (DMS) nanostructures, we tried to manipulate the performance of DMS-based devices. Under hydrothermal conditions, self-assembled complex nanostructures (flowers, sheaves, and cactuses) of Co-doped ZnO DMS thin films were selectively grown. Based on detailed scanning electron microscopy, energy-dispersive X-ray analysis, the sensitivity of the grazing incidence X-ray diffraction and transmission electron microscopy, the possible growth mechanism and phase analysis of the Co-doped ZnO nanostructures were proposed. The observation demonstrates that through self-assembly of 1D primary nanoparticles via oriented attachment or twinning coalescence, the transformation to 3D complex nanostructures was controlled. These novel Co-doped ZnO nanostructures exhibited enhanced ferromagnetism that can potentially improve the performance of spintronic devices. Our findings provide a better insight into the underlying growth mechanisms of the ferromagnetic Co-doped ZnO nanostructures.

Pollution resulting from textile industries wastewater, affects aquatic life, groundwater, crops, and human life. Hence, using membrane-based filtration technology to treat produced water opens new avenues for water recovery. In this work, polyvinylidene fluoride (PVDF) membranes with triethanolamine (TEA) and polyethylene glycol (PEG) were synthesized and tested as ultrafiltration (UF) materials for textile wastewater removal. PVDF UF membranes were synthesized by phase inversion method with different additives ratios (0, 1:0,1:1, 2:1, 2:2 of M0, M1, M2, M3, M4, respectively) of TEA and PEG. The PVDF UF membrane’s performance (water flus and dye rejection) was evaluated by synthetic disperse dyes and real textile industrial wastewater. The physical and chemical structure of PVDF UF membranes was investigated using FTIR, SEM, elongation, tensile strength, porosity, water uptake rate (WUR) and water contact angle (WCA) techniques. In comparison to virgin membrane (M0), the M2 UF membrane exhibited higher than 97.3% dye rejection for both disperse dyes removal with flux of 100 LMH due to the formation of dense sponge pores in the top layer with microvoid near the bottom, leading to high rejection with reasonable flux and cost-effective procedures. While for real textile industrial wastewater, M2 showed a good rejection of 90.4% and flux of 53.1 LMH due to other complications of suspended solids, organic aggregates, salts, etc. real sample. In the same line, this optimum M2 UF membrane demonstrated tensile strength of 8.6 MPa, porosity of 30.8%, WUR of 57.5%, and WCA of 78. Eventually, the prepared membranes have high dye removal efficiency and the treated water can be directly reused within the same textile industry in scouring and finishing processes, washing tanks, cooling towers, washing earth, and planting nonedible plants. Graphical abstract