Shawon Saha

Sr _x La _{2– x} NiMnO ₆ , a bi-functional adsorbent and photocatalyst for trypan blue adsorption with UV-driven in situ regeneration, enabling adsorbent reuse.

A simple sol-gel method was developed to synthesize La2NiMnO6 (LNMO) double perovskite in nano dimensions, which was evaluated for the effective adsorptive removal of m-cresol from aqueous solutions. The structural and chemical properties of the synthesized LNMO were characterized using X-ray Diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Field Emission Scanning Electron Microscopy (FESEM), and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The LNMO material possessed a hexagonal crystal structure and an average particle size of approximately 50 nm, which contributed to improving adsorptive properties. Furthermore, adsorption studies revealed that m-Cresol removal is significantly pH dependent, as maximum adsorption was found at pH 2. As a weak acid, m-cresol exists in its neutral form in acidic conditions and promotes interaction through hydrogen bonding and Lewis acid-base interactions with LNMO's surface. Moreover, adsorption isotherms were analyzed using Langmuir, Freundlich, and Temkin model where the Langmuir model fitted the best, indicating a maximum adsorption capacity of 204 mg/g while the values of Langmuir equilibrium constant (KL) of 0.1158 L/mg, and a dimensionless constant (RL) of 0.256, suggesting a favorable adsorption process. Thermodynamic parameters like Gibbs free energy (ΔGo), enthalpy (ΔHo), and entropy change (ΔSo) were analyzed, and it revealed that the adsorption process is spontaneous, heat-releasing, and leads to reduced randomness at the solid-liquid interface. Hence, this study demonstrates the exceptional potential of LNMO as an efficient, cost-effective adsorbent for m-cresol removal, offering valuable insights for the development of novel material for wastewater treatment. Dhaka Univ. J. Sci. 74(1): 17-26, 2026 (January)

Reline-assisted synthesis of fcc-hcp Ni/Ni(OH) ₂ nanocatalyst for effective reductive hydrogenation of 4-nitrophenol with 95% efficiency a high rate constant (k = 0.1336 min ⁻¹ ), demonstrating excellent catalytic performance.

Researchers have significantly focused on eco-friendly methods for nanomaterial synthesis to reduce the reliance on hazardous chemicals. In light of this, this study presents an eco-friendly, straightforward, alkali-free method for synthesizing iron–manganese (Fe–Mn) binary oxide (FMBO) and their single oxides by adopting a direct gel formation approach using starch. The synthesized materials were characterized through FTIR, FESEM, EDX, and XRD. Based on the characteristics of the synthesized materials, the probable formation mechanism of nanomaterials within the starch matrix via gel formation was comprehensively investigated. The presence of MnO₄ ⁻ resulted in faster gelation than Fe³⁺ owing to its stronger oxidizing properties, leading to a more robust gel network that could stabilize nucleation, control the growth of nanoparticles, and thereby reduce particle agglomeration. The synthesized materials were further employed for the adsorptive removal of arsenic, and the findings demonstrate that FMBO was much more effective than the individual oxides in simultaneously eliminating arsenic species (III and V) with an adsorption capacity of 79 mg g⁻¹ for total arsenic (As(III) + As(V)) owing to its nanostructure, surface characteristics, and synergistic effects of Fe and Mn oxides. Our observation suggests that Mn oxide pre-oxidizes As(III) to As(V), which is then efficiently adsorbed by Fe oxide. This study underscores the potential of starch-based nanomatrices in developing efficient materials with enhanced properties.