Search

Herein, we report the synthesis of novel platinum-based nanoparticles with step-pyramidal growth induced by poly(diallyldimethylammonium chloride) (PDDA). The complex stepped pyramidal shape became the central point for outstanding catalytic reduction of 4-nitrophenol, overcoming the activity of bare Pt nanoparticles. These results are valuable for the catalytic degradation of reactive molecules. [ABSTRACT FROM AUTHOR]

The aim of this report is to synthesize copper oxide nanocubes (CuO NCs) at room temperature, using sodium borohydride as a reducing agent, and Cetyl Trimethyl Ammonium Bromide (CTAB) as a stabilizing agent. The crystallinity and morphology of the synthesized CuO NCs are investigated via X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscope (TEM). The optical properties were analyzed by means of UV–visible absorbance and Raman spectroscopy. The existence of specific functional groups and structural stability were established via FTIR spectroscopy and thermogravimetric analysis (TGA). Furthermore, the catalytic efficiency of the as-prepared CuO NCs was tested using catalytic and photocatalytic studies of para-nitrophenol (p-NP) reduction and methylene blue (MB) degradation, respectively. The catalytic results demonstrated the nanocubes' excellent catalytic and photocatalytic responses with respect to the abatement of p-NP and MB within 50 s and 240 min, with kinetic rate constants of 3.9 × 10−2 s−1 and 6.47 × 10−3 min−1, respectively. [ABSTRACT FROM AUTHOR]

The task of creating a remarkably stable and effective electrochemical catalyst for efficient hydrogen evolution is arduous, primarily due to the multitude of factors that need to be taken into account for the industrial utilization of Pt. In this work, hybrid formation through in-situ reduction of Pt onto biogenic porous silica (Pt-SiO 2 ) is tested for its use as an efficient catalyst for hydrogen production. Exceptionally high electrocatalytic activity and excellent reusability of catalysts up to 200 cycles have been demonstrated. Pt-SiO 2 with low Pt content of 0.48 to 0.82 at% with active catalytic sites exhibit superior catalytic activity with a Tafel slope of 22 mV dec -1 and an overpotential of 28 mV (vs. RHE at 10 mA cm -2 ) as compared to the Pt wire and previously reported bare Pt-SiO 2 (0.65 at% and 0.48 at% of Pt), and hybrid (Pt/Ag) structures formed onto two different biogenic porous SiO 2 substrates. The best catalytic performance of the Pt 1 Ag 3 cluster, representing a low Pt concentration, has been validated by Density Functional Theory (DFT) calculations. Here, the high production from the Pt 1 Ag 3 cluster is assigned to the mutual synergistic effect between Pt/Ag atoms. The Pt atoms transfer the excess charge to the nearest Ag neighbors inside the cluster, facilitating hydrogen diffusion on the activated sites. These important findings authenticate the superior hydrogen production at reduced Pt concentration on amine-functionalized biogenic porous silica., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Fluorescent nitrogen-doped graphene oxide dots (NGODs) have been demonstrated as an on-off nanosensor for the detection of Hg 2+ , Au 3+ , and H 2 O 2 . As compared to l-cystine, where the luminescence signal recovery results from the detachment of Hg 2+ from the NGODs, signal recovery through l-ascorbic acid (turn-off-on model) has been attributed to the reduction of Hg 2+ to Hg 0 . The sustainable recovery of the photoluminescence signal is demonstrated using common citrus fruits containing vitamin C (l-AA), suggesting a promising practical usage of this sensing system. Additionally, the sensitivity of NGOD- and AA-originated signal recovery from the Hg(II)-NGODs mixture has been successfully tested in Hg 2+ ion-spiked tap water from three different places. Mimic devices were executed and verified on the basis of characteristic spectral changes, and the possible utility of this system in electronic security and memory element devices has also been demonstrated. Considering an easy synthesis process and excellent performance of NGODs, this investigation opens up new opportunities for preparing high-quality fluorescent NGODs to meet the requirements of many applications., Competing Interests: The authors declare no competing financial interest.