Search

In this work, a photoelectrochemical reactor with an anode based on hybrid structure between conducting polymer polypyrrole (PPy) and porous silicon (PSi) was fabricated and utilized to evaluate the photocatalysis and electro‐assisted photocatalysis for degradation of rhodamine B (RhB) solution. The PSi was made of n‐type silicon single‐crystal wafer by the metal‐assisted chemical etching (MACE). The anode PPy/PSi formed following a polymerization of the PPy on the PSi from the vapour‐phase route using oxidant FeCl3. Typical material characterizations of the PPy, PSi and PPy/PSi were investigated via scanning electron microscope (SEM), and spectroscopies of Fourier‐transform infrared (FTIR), Raman scattering and UV‐vis. Under visible light radiation (halogen light with the wavelength region of 400–700 nm), photocatalytic and electro‐assisted photocatalytic processes of the reactor were conducted by degradation of the RhB solution. A heterojunction (p‐n) of the PPy/PSi was proposed to explain the efficient catalytic performance of the reactor. [ABSTRACT FROM AUTHOR]

We report preparation and characterization of Si1-xGex alloys with varied composition x of a large range from 0-1. The materials have been obtained by co-sputtering, followed by a heat treatment process at 600, 800, and 1000 °C for 30 min in a nitrogen gas atmosphere. X-ray diffraction data have revealed the formation of single-phase nanoparticles in the face-centered cubic (FCC) structure of Si1-xGex alloys. We found that lattice constant a of the Si1-xGex alloys increased linearly with the composition parameter x. Average diameters of the single-phase nanoparticles were estimated to be between 3-10 nm. Further evidence of FCC single-phase [Formula: see text] nanoparticles has been obtained by high resolution transmission electron microscopy. From absorption spectra, the gradual shift of the direct phononless transition identified for the E1 point in the Brillouin zone of bulk Ge is observed in single-phase Si1-xGex nanoparticles as a function of the composition parameter x.