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The development of a fluorescent pH sensor and the treatment of wastewater with nanoparticles are both critical topics. Variations in pH impact the morphology and subsequent properties of nanoparticles, affecting their utilization in various fields, while using nanoparticles offers an improved approach for treating industrial waste. The present study examines the effects of these variables on biologically produced nitrogen-doped carbon quantum dots (NCQDs). The synthesis was achieved through a hydrothermal process using Rubus niveus leaf extract as a precursor. UV-Vis spectroscopy analysis revealed absorption spectra over a wide range from 200 nm to 800 nm, with prominent peaks at 236 nm and 392 nm. Additionally, the direct energy band gap of the NCQDs was found to be 3.65 eV. SEM imaging displayed flower-shaped particles, and FT-IR analysis indicated the presence of amide, CHO, N-H, and C-N functional groups. The XRD pattern revealed that the surface morphology of NCQDs is amorphous in nature. A significant response in fluorescence intensity with varying pH values was observed, confirming the potential of NCQDs as pH sensors. The reaction kinetics of Rhodamine-B (Rh-B) dye was analyzed to assess the potential of NCQDs for dye degradation, revealing pseudo-first-order kinetics with a correlation coefficient of 0.80. [ABSTRACT FROM AUTHOR]

This study investigates the three-dimensional problem of steady ferrofluid deposition on an inclined rotating surface in the presence of a magnetic dipole. A finite element procedure is used to solve normalized ordinary differential equations derived from momentum and energy equations. The current numerical model and its solution is compared and validated against previous numerical results. The velocity and temperature field variations are a representation of the effects of magnetic field-based viscosity, magnetic polarization force, Curie temperature, and Prandtl number. In addition, some common errors in the similarity transformation for inclined rotating disk flows are addressed in the present study. The results show that the magnetic field-dependent viscosity generated by the magnetic torque in the current flow reduces the velocity of the thin film liquid in all directions, including rotational flow (radial, tangential, and axial) and inclined flow (drainage and induced). Moreover, the local heat transfer between the fluid and the surface of the rotating disk increases with a rise in the ferromagnetic interaction number and Prandtl number. These findings imply that ferrofluids could be effective for cooling electronic devices in the presence of a magnetic dipole. [ABSTRACT FROM AUTHOR]

Surface enhanced Raman scattering (SERS) study is an interesting active area of research, where periodically patterned plasmonic substrates play a key role in SERS enhancement. Surface plasmon resonance excitation generates tremendous electromagnetic near-fields (E) in the form of localized or propagating near-fields contributing to the Raman signal (E4 process) to a great extent and overall enhancement is reported to be as high as 1010 or even more. Independently, graphene alone can enhance the Raman signal due to chemical enhancement. In the present study, we have attempted to achieve high SERS from the R6G Raman active probe using plasmonic patterned substrates in the presence and absence of graphene oxide. Plasmonic ladder-like patterned substrates are fabricated using laser interference lithography, which is cost effective, simple to operate, and has potential for large scale nanofabrication. By combining graphene oxide with R6G, we have found additional two time enhancement compared to that obtain from R6G alone on the plasmonic patterned substrate. Further, we have also attempted to understand the underlying mechanism to correlate the uniform and reproducible SERS through Raman mapping and Finite difference time domain computation. Our finding can potentially be applied for SERS investigation at a low molecular concentration. [ABSTRACT FROM AUTHOR]

A novel rapid (∼10 min) microwave-hydrothermal synthesis is demonstrated for nanorice TiO2mesoparticles as an anode of a dye-sensitized solar cell with an excellent photovoltaic efficiency of above 8%. [ABSTRACT FROM AUTHOR]

We report a significant enhancement in the thermoelectric power of PEDOT by fabricating a novel ternary composite film by incorporating Bi 2 Te 3 and rGO. A series of five samples of PEDOT:PSS/Bi 2 Te 3 /rGO ternary composite films were synthesized using a spin coating method and having different weight% (0.0, 0.1, 0.2, 0.3 wt%) of rGO in PEDOT:PSS/0.4 wt% Bi 2 Te 3 mixture along with pure PEDOT:PSS sample. The Seebeck coefficient, electrical conductivity, and power factor increased in composite films compared to pure PEDOT:PSS films. Incorporating rGO enhanced charge carrier mobility because of its highly conductive network, whereas Bi 2 Te 3 provided higher Seebeck coefficients owing to its inherent thermoelectric properties. PEDOT:PSS offered mechanical flexibility and a conductive matrix, facilitating effective phonon scattering and inherently lower thermal conductivity. The sample (PEDOT:PSS/0.4 wt% Bi 2 Te 3 /0.1 rGO wt%) demonstrated the highest electrical conductivity of 1522.4 S cm -1 , a Seebeck coefficient of (+) 24.7 μV K -1 , and a power factor of 93.16 μW m -1 K -2 at room temperature. These values represent a twelve-fold increase compared to pristine PEDOT films. A flexible, printable thermoelectric generator (TEG) was also demonstrated on polyimide substrate using inks prepared from p-type PEDOT:PSS/Bi 2 Te 3 /rGO and n-type PVDF/Ni NWs. The paper TEG achieved a maximum power output of 242.1 nW, with an output voltage of 9.84 mV and an output current of 49.21 μA at a temperature difference (Δ T ) of 35 K. XRD, Raman spectroscopy SEM, and XPS techniques were used to understand the underlying mechanism. This novel PEDOT:PSS/Bi 2 Te 3 /rGO ternary composite film significantly outperforms previously reported organic thermoelectric materials. The results indicate that the combined effect of PEDOT:PSS, Bi 2 Te 3 , and rGO greatly enhances thermoelectric performance, offering a promising and efficient route for the application of PEDOT in advanced thermoelectric conversion processes., Competing Interests: The authors declare that there is no conflict and competing interest that could have appeared to influence the paper., (This journal is © The Royal Society of Chemistry.)