Long single crystalline α-Mn2O3 nanorods: facile synthesis and photocatalytic application

Single crystalline cubic sesquioxide bixbyite α-Mn2O3 nanorods have been synthesized successfully by a simple, low cost, environmental benign hydrothermal route. As synthesized γ-MnOOH were calcined at 600 °C to obtain α-Mn2O3 nanorods, which were further subjected to various characterizations. The alpha manganese sesquioxide cubic bixbyite-type oxide formation was confirmed by the XRD studies. The surface morphology and elemental analysis were explored by SEM with EDX studies, respectively. High-resolution transmission electron microscopy HRTEM and SAED showed that the α-Mn2O3 nanorods were single crystalline and were grown along the C-axis of the crystal plane. The UV–visible spectrum indicated that the absorption was prominent in the ultraviolet region. In addition, PL spectrum result of α-Mn2O3 nanorods recommended possible photocatalytic applications. The photocatalyst ensures a new platform for the decolorization of dye molecules of the harmful cationic dyes like methylene blue and rhodamine B. Possible growth mechanism and photocatalytic dye degradation mechanism were proposed for synthesized α-Mn2O3 nanorods

Ti₃C₂T_x MXene decorated with NiMnO₃ / NiMn₂O₄ nanoparticles for simultaneous photocatalytic degradation of mixed cationic and anionic dyes

The present report investigated the different mass ratios of Ti3C2Tx MXene decorated NiMnO3 / NiMn2O4 nanoparticles and their enhancement of photocatalytic performance. The NiMnO3 / NiMn2O4 - Ti3C2Tx MXene nanocomposites were synthesized by a simple electrostatic self-assembly method. The physicochemical properties of nanocomposites were analyzed by XRD, SEM, and FESEM with EDAX, FTIR, PL, and UV-Visible spectrometer. The rhombohedral / cubic spinel structure of NiMnO3 / NiMn2O4 was confirmed by the XRD. The SEM and FESEM morphology show that spherical NiMnO3 / NiMn2O4 nanoparticles were decorated on the Ti3C2Tx MXene sheets and also present on the inside of the Ti3C2Tx MXene sheets. The average diameter of NiMnO3 / NiMn2O4 nanoparticles (46 nm) and the interlayer spacing of Ti3C2Tx MXene sheets (56 nm) were measured from FESEM analysis. The energy bandgap of NiMnO3 / NiMn2O4 - MXene nanocomposites was determined as ranging from 1.2 eV to 0.8 eV. The Ni, Mn, O, Ti, C, and F elemental compositions of the composites were analyzed by the EDAX. The effective photo-generated electron transferring from NiMnO3 / NiMn2O4 to Ti3C2Tx MXene was established by the PL quenching of NiMnO3 / NiMn2O4. The 100% degradation efficiency was achieved in methylene blue (MB). The mixed dye degradation rates achieved for Rhodamine B (RhB), methyl orange (MO), and methylene blue (MB) for 90%,72%, and 100% after 50 min in the presence of NiMnO3 / NiMn2O4 -Ti3C2Tx MXene (20 wt. %). According to a scavenger experiment, the predominant species actively involved in the photodegradation process were revealed to •OH and •O2-.</p