In order to answer the question of whether Schottky barriers on polar ZnO surfaces are different at Zn- and O-terminated surfaces, the interface formation of $n$-type ZnO and different high work function metals and metal oxides (Pt, ${\mathrm{PtO}}_x$, and ${\mathrm{RuO}}_2$) with Schottky barrier heights of up to 1.5 eV has been studied using photoelectron spectroscopy with in situ sample preparation. The experiments are designed to exclude the effects of substrate reduction and consequent Fermi level pinning by high concentrations of oxygen vacancies. Moreover, by including the Zn LMM Auger emission in the analysis, it is demonstrated that an accurate extraction of barrier heights needs to take into account that the screening of the photoelectron core hole can change in the course of contact formation. The polarization dependence of Schottky barriers, which is important for piezotronic applications, is in most cases dominated by the influence of defects. Reducing the influence of defects, up to $\sim 240$ meV higher Schottky barriers are revealed on oxygen-terminated surfaces. This is opposite to what has been reported in the literature but agrees with the dependence of barrier heights expected for an incomplete screening of the polarization of ZnO by the electrode as for ferroelectric materials.

Modern bioimplants increasingly depend on surface-engineered functionality to elicit adaptive biological responses. One promising strategy involves the electrodeposition of bioresponsive elements such as magnesium (Mg), which plays a critical role in osseointegration. In this study, we present a novel approach for modifying anodized zirconia nanotubes (ZrNTs) via Mg decoration using electrochemical deposition. A controlled pulsed cathodic linear sweep protocol was employed to control Mg deposition behaviour, enabling reduced clustering and improved spatial distribution. Notably, ultraviolet (UV) irradiation was found to influence Mg adsorption dynamics, revealing a distinct pattern of interaction. Comprehensive surface characterization was conducted to assess nanotube morphology, Mg adherence, and distribution. These modified surfaces were subsequently evaluated for their potential in further functionalization, targeting surface chemistries conducive to biomaterial viability. The biomineralization capacity of Mg-decorated ZrNTs was systematically investigated using electrochemical impedance spectroscopy (EIS) and Tafel analysis, demonstrating enhanced apatite formation and improved corrosion resistance. This work establishes Mg decoration of ZrNTs as a viable route for developing bioactive, corrosion-resistant implant surfaces.

Single atom photocatalysts (SAPCs) offer maximum atom efficiency and unique catalytic behaviour, presenting a promising path toward economically viable and sustainable catalytic systems. However, the rational design and optimization of such materials by gathering atomic-level evidence using high-end characterization tools remain challenging due to their cost and limited accessibility. In this work, we demonstrate a simple, integrated approach to fabricate, investigate and optimize SAPCs. An energy-efficient electrochemical approach for fabricating Cu-based single-atom sites on titanium dioxide nanotubes (TiNT) arrays was developed to achieve strong metal-support interaction. The immobilized TiNT framework provides ordered electron transport pathways and strong anchoring sites for Cu adherence, while the electrochemical conditions dictate whether Cu atoms evolve as isolated sites or aggregate into clusters. Although in general, electrochemical strategies for the synthesis of single atoms on oxide offer precise control over deposition, their effectiveness critically depends on the underlying deposition dynamics. Therefore, we have investigated the influence of deposition mode on the formation and dispersion of Cu single atoms, redox coupling strength and electronic structure within these systems, using X-ray Photoelectron Spectroscopy (XPS), Electron Paramagnetic Resonance (EPR) and Time-of-Flight Secondary Ion Mass Spectroscopy (ToF-SIMS). XPS and EPR analysis indicates that Linear Sweep Voltammetry (LSV) deposition produces clustered Cu species, whereas pulsed LSV (pLSV) leads to atomically dispersed Cu centres. ToF-SIMS spectra suggest increased CuO-/Cu- ratio consistent with evidence seen in XPS and EPR. Together, these complementary observations confirm that pLSV enables efficient stabilization of atomically dispersed Cu sites through interfacial redox coupling strength modulation and clustering suppression. With this we have shown that a multi-modal approach with the strategic and integrated use of XPS, EPR, and ToF-SIMS can enable efficient screening of single-atom catalysts during the design stage.

Self-assembled monolayers (SAMs) on metal oxides play a pivotal role in tailoring surfaces for advanced hybrid and nanoscale architectures; however, their adsorption behavior is strongly governed by the interfacial chemistry of the underlying oxide. In this study, we systematically investigate the adsorption characteristics of two model acidic and basic SAM molecules with identical 12-carbon alkyl chains, tridecanoic acid (TDA) and dodecylamine (DDA), on WO3, TiO2, and NiO surfaces. These organics exhibit distinct dissociation mechanisms and surface affinities, enabling a detailed comparison across oxides with markedly different isoelectric points (IEPs). WO3 and TiO2 possess low IEPs (~3 and ~4), whereas NiO shows a significantly higher IEP (~10), providing a well-defined platform for probing the influence of surface charge on SAM adsorption. Leveraging these insights, we further fabricated TiO2-NiO composite substrates to assess the potential for area-selective SAM functionalization driven by IEP contrast. Comprehensive characterization combining contact angle measurements, XPS and ToF-SIMS was employed to quantify surface coverage and elucidate chemical and elemental compositions. The findings show that each SAM exhibits a clear preference for particular oxide surfaces based on surface charge interactions, enabling selective molecular modification of composite-oxide substrates and providing new opportunities for constructing advanced three-dimensional hybrid organic-inorganic architectures.