Arrays of ZnO nanorods (NRs) were successfully converted into nanotubes (NTs), used as photoelectrodes in photoelectrochemical (PEC) cells after their sensitization with CdSe quantum dots (QDs) and a strong correlation between the PEC performance and geometrical structure of ZnO NTs@CdSe(QDs) and ZnO NRs@CdSe(QDs) was established under the same conditions.

Day by day augmenting importance of metal nanoparticles in the versatile fields like, catalyst, electronic, magnetic, mechanic, optical optoelectronic, materials for solar cell and fuel cell, medical, bioimaging, cosmetic, ultrafast data communication and optical data storage, etc, is increasing their value. Nanoparticles of alkali metals and noble metals (copper, silver, platinum, palladium, and gold, etc.) have a broad absorption band in the visible region of the electromagnetic spectrum of light, because the solutions of these metal nanoparticles show the intense color, which is absent in their bulk counterparts as well as their atomic level. The main cause behind this phenomenon is attributed to the collective oscillations of the free conductive electrons that are induced by an interaction with electromagnetic field. The whole incidence is known as localized surface plasmonic resonance. Out of these, we have selected the silver nanoparticles for the studies. In this article, we will discuss the synthesis, characterization, and application of the silver nanoparticles. Future prospective and challenges in the field commercialization of the nanosilver is also discussed.

Enhanced visible light photocatalytic activity of Gd‐doped CeO 2 nanoparticles (NPs) is experimentally demonstrated, whereas there are very few reports on this mechanism with rare earth doping. All‐pure and Gd‐doped CeO 2 NPs are synthesized using a coprecipitation method and characterized using X‐ray diffraction (XRD), absorption spectroscopy, surface‐enhanced Raman Spectroscopy (SERS), X‐ray photoelectron spectroscopy (XPS), and superconducting quantum interference device (SQUID). The effect of Gd‐doping on properties of CeO 2 is discussed along with defects and oxygen vacancies generation. The XRD confirms the incorporation of Gd 3+ at the Ce 3+ /Ce 4+ site by keeping the crystal structure same. The average particle size from transmission electron microscopy (TEM) images is in the range of 5–7 nm. The XPS spectra of Ce 3d, O 1s, and Gd 4d exhibits the formation of oxygen vacancies to maintain the charge neutrality when Ce 4+ changes to Ce 3+ . The gradual increase in hydrogen production is observed with increasing Gd concentration. The observed results are in good correlation with the characterization results and a mechanism of water splitting is proposed on the basis of analyses. The absorption spectra reveal optical band gap (2.5–2.7 eV) of samples, showing band gap narrowing leads to desired optical absorbance and photoactivity of NPs.

No abstract

Here, we present the reduction of the graphene oxide (GO) sheets by means of the two reducing agents, i.e., ascorbic acid and lemon juice. As-prepared carbonaceous substances (rGO-AA and rGO-Lemon) exhibits good room temperature (RT) ferromagnetism even in absence of dand f-electrons as well as they show good hydrogen generation capacity via photocatalytic water splitting. The amount of H 2 evolved for Pt/GO, Pt/ rGO-AA, and Pt/rGO-Lemon systems was 32.0790, 23.1649, and 38.0790 mmol h −1 g −1 , respectively. The results go hand in hand and are supported by the reasonably good spin concentration due to the presence of a large amount of the free-radical-like carbon, long-range direct/indirect exchange or interaction between graphene matrix, fragmented graphitic zones, C-defect nonbonding localized electronic states, and flat-band quasi-localized (QL) states induced by the point defects.

Aqueous chemically grown ZnO nanorods ͑NRs͒ arrays were sensitized by CdSe quantum dots ͑QDs͒ and were investigated as photoanode for photoelectrochemical water splitting under visible light ͑Ͼ420 nm͒ illumination. Significant enhancement of the factors 1.6 and 6 was observed for CdSe ͑QD͒-sensitized nonannealed and annealed samples of ZnO NRs over pristine ZnO NRs arrays, respectively. The highest photocurrent density of 2.48 mA/cm 2 was registered for the annealed CdSe ͑QD͒/ZnO ͑NR͒ arrays films at zero applied voltage and 100 mW/cm 2 ͑AM 1.5 G, Air Mass 1.5 Global͒ power density and their corresponding photocurrent density for pristine ZnO NR array was recorded as 0.41 mA/cm 2 .

No abstract

No abstract