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The work shows the possibility of obtaining active platforms for surface-enhanced Raman scattering (SERS) measurements based on TiO2nanotubes decorated with Ag, Au, or Au–Ag bimetallic layers. Plasmonic metallic layers were produced under ultra-high vacuum (UHV) conditions using the thermal evaporation method and heat treatment, which enabled them to be formed with a precisely defined thickness and size of metallic nanoparticles. The two-stage thermal treatment leads to the formation of an Ag–Au bimetallic alloy on the top of the nanotubes. In all cases, the thickness of the deposited metal layer was 10 nm. Therefore, the materials prepared in the form of decorated nanoplasmonic antennas (nanobrushes) were tested for their use as active and effective substrates in SERS spectroscopy. For this purpose, the probe molecule mercaptobenzoic acid (MBA) was used. The highest SERS enhancement factor was determined for the substrate with a monometallic Ag layer (1.5̇̇ × 105), then for the Ag–Au alloy (1.7 × 104), monometallic Au layer (9.6 × 103), and gold/silver layer-by-layer systems (∼5.6 × 103). The practical usefulness of the prepared SERS substrates was determined based on vitamin B12 detection measurements. The results showed that the proposed SERS substrates have a high detection sensitivity of 10–8M and measurement stability. Moreover, the conducted research showed that the most important factors influencing the enhancement due to the electromagnetic mechanism are geometric factors related to the distribution of plasmonic metals on the tops and walls of nanotubes, their size, and chemical composition. Moreover, the chemical composition of the examined deposits turned out to be an important factor affecting the plasmonic properties of the produced SERS platforms. Apart from SERS spectroscopy, other research methods were used to characterize the obtained materials, such as UV–vis spectroscopy, XPS spectroscopy (in situ), XRD structural analysis, and scanning electron microscopy.

Heterojunction engineering enables more versatile and higher performance systems than single components. In parallel with heterojunction engineering, defect engineering has emerged as a means of tailoring the optoelectronic properties of photoelectrodes. However, constructing effective and stable hybrid semiconductor heterojunctions is a challenging task under the strict requirements of band alignment, vacancy characteristics, and interface properties. Herein, the photoelectrochemical (PEC) reduction of CO2to methanol is augmented by a novel approach explored by modeling the Fermi level in a multi‐interface architecture. The excellent PEC CO2reduction activity is attributed to the formation of a high‐performance, energetically aligned multi‐interface system of CuO/Cu2O||rGO|h‐WO3|rGO (rGO = reduced graphene oxide layer). The overall performance of this hybrid, system strongly depends on the number of oxygen groups in rGO and the structural properties of rGO. Therefore, to construct an effective PEC system, numerous postsynthetic treatments are explored for their practicality and usefulness. The results reported herein clearly show that the best performance toward the CO2photoreduction currents of 3 mA/cm2at 0.00.1 V versus reversable hydrogen electrode (more than double that of the CuO/Cu2O system) has been reached for the semiconductor architecture containing two layers of rGO. The enhanced photoelectrochemical (PEC) CO2reduction performance is investigated by step‐by‐step multiinterface structure optimization, followed by band energetics alignment in CuO/Cu2O||rGO|h‐WO3|rGO. Therefore, numerous postsynthetic treatments and geometries are explored for their usefulness for solar CO2conversion to fuels. The findings provide an explanation for the nature of CO2activation and relationship between its stability and other structural and spectral properties.

We investigated the structure and photo-electrochemical properties for water splitting of tungsten trioxide-ferric oxide thin films formed by spray pyrolysis. While annealing at 600°C produces films consisting of a mixture of monoclinic WO3and hematite α-Fe2O3, the heating at a temperature above 1000°C affords formation of ferric tungstate Fe2WO6. Both kinds of films exhibit optical absorption range comparable or exceeding that of α-Fe2O3. Another important feature is a decreased rate of charge recombination of the mixed-oxide Fe2O3-WO3with respect to the ferric oxide photo-anodes.