The integration of light harvesting with electrochemical energy storage has been increasingly recognized as a promising pathway to address the global energy crisis. By directly coupling photon absorption with ion storage processes, photo-assisted energy storage systems offer unique advantages over conventional batteries and capacitors. This intrinsic synergy not only enhances device performance but also opens new opportunities for solar-rechargeable energy storage technologies. Among various aqueous energy-storage systems, ammonium-ion-based devices have recently emerged as promising candidates owing to the unique hydrogen-bond-driven insertion mechanism of NH4+, which enables fast ion transport and high reversibility in mild aqueous electrolytes. Integrating such NH4+ storage chemistry with photoactive electrodes could further expand the functionality of aqueous systems toward light-assisted charge storage. Married this context with ammonium-ion hybrid supercapacitors (AIHSs), this concept represents an attractive and novel aqueous energy storage system, thanks to their low cost, intrinsic safety, environmental benignity, and unique hydrogen-bond-driven insertion mechanisms. To achieve these distinctive features, AIHSs particularly need to be coupled with photoactive electrodes featuring both high-performance and light-enhanced charge storage. This dissertation thus focuses on the rational design of WO3-based electrode owning photo-enhanced functionality for efficient ammonium-ion storage. Through the development of folded nanocrystalline–amorphous WO3 structures, WO3/TiO2 heterojunctions, and WO3/BDD composites, this work systematically establishes structure–property–performance relationship and demonstrates new design principles to construct high-performance, solar-responsive aqueous energy storage devices. Three experimental parts are detailed as follows. I) Folded nanocrystalline–amorphous WO3 electrodes: The folded nanocrystalline-stacked amorphous WO3 (a-WO3) electrodes were synthesized via a rapid electrochemical deposition method. They own hierarchical frameworks where ~5 nm crystallites are loosely assembled within an amorphous matrix. Their comprehensive characterization was conducted using microscopy, spectroscopy, electrochemical techniques, and density functional theory simulations. More importantly, the relationship between structural architecture, defect chemistry, and NH4+ storage performance was investigated in detail. The a-WO3 electrodes demonstrated superior electrochemical activity with a capacitance of 2783 mF cm−2 and excellent rate performance compared to crystalline counterparts. The amorphous structure is confirmed to provide abundant grain boundaries, oxygen vacancies, and mixed-valence tungsten states, facilitating rapid NH4+ transport through hydrogen bonding mechanisms. As a demonstration, the a-WO3 electrode was employed to construct a full ammonium-ion hybrid supercapacitor with a polyaniline cathode. This supercapacitor delivers remarkable energy and power densities of 620 mWh cm−2 and 23,980 mW cm−2, respectively, further with 81.5% capacity retention after 3000 cycles. These results highlight the effectiveness of controlled amorphization as a strategy to overcome the intrinsic limitations of crystalline WO3 and achieve both high capacity and durability. All these are shown in Chapter 3. II) WO3/TiO2 heterojunctions for light-assisted energy storage: The WO3/TiO2 heterojunction composites were designed with an aim to harness photo-enhanced energy storage capabilities through synergistic light and electrochemical properties. The band alignment between WO3 and TiO2 was utilized to engineer Type II heterojunctions, which leverage the superior photocatalytic activity of TiO2 and charge separation capability, eventually enhancing electrochemical performance of WO3. Through controlled electrochemical deposition parameters, island-like distributed WO3 nanocrystals have been coated on TiO2, ensuring simultaneous exposure of both materials to the electrolyte and meanwhile achieving true synergistic effects rather than simple serial coupling. This island-like growth mode maximizes the heterojunction interface area, promoting efficient charge separation and transport. The TiO2 component provides superior photocatalytic activity and extends the photoactive spectral range, while WO3 offers high-capacity NH4+ storage capability. Comprehensive characterization of these composite electrodes reveals their enhanced light absorption, improved charge carrier dynamics, and accelerated ion transport kinetics under illumination. Under light irradiation, the typical composite material showed 40% capacity enhancement compared to that under dark conditions, with a significantly reduced charge transfer resistance by a factor of 80-85%, a photocurrent density of 0.47 mA cm−2, and substantially improved carrier density and interfacial kinetics. All these validate the effectiveness of heterojunction design in achieving photo-assisted energy storage. These details are summarized in Chapter 4. III) WO3/BDD p-n junction for light-assisted energy storage: This session addresses the persistent conductivity limitations of WO3 electrodes by incorporating boron-doped diamond (BDD), a carbon material known for its wide potential window, high conductivity, and chemical robustness. The strategic combination creates a p–n junction configuration that exploits the ultra-wide bandgap of diamond (5.5 eV) and the superior electronic properties of p-type BDD interfaced with n-type WO3. The intrinsic electric field at the junction enhances charge separation efficiency, while the exceptional conductivity of BDD complements the NH4+ storage capability of WO3. Compared with pristine WO3, the composite delivered a ~1.7-fold higher photocurrent density and the areal capacitance under light was enhanced by nearly 20%. In addition, the electrode maintained over 90% of its capacity after extended cycling, outperforming pristine WO3. Therefore, the WO3/BDD p–n junction delivers significantly enhanced photocurrent response, improved NH4+ storage capacity under illumination, and extended cycling lifetime compared to pristine WO3. The built-in electric field facilitates directional charge transport and suppresses recombination losses, resulting in superior photoelectrochemical performance. These results are demonstrated in Chapter 5. In summary, this thesis provides several successful approaches to design and optimize WO3-based electrode materials for sustainable ammonium-ion energy storage applications in the way of both advanced structural engineering and innovative photo-enhancement strategies. By developing folded nanocrystalline-stacked architectures, engineering Type II and p-n heterojunctions, and integrating photocatalytic functionalities, the great potential of WO3 in achieving high-performance, environmentally friendly energy storage devices have been proved in this thesis. They also feature dual solar energy harvesting and electrochemical storage capabilities. Such systematic investigation of photo-assisted mechanisms clarifies that heterojunction formation enables efficient charge separation, reduces recombination losses, and significantly enhances electrochemical performance under illumination. This work establishes fundamental design principles for photo-responsive electrode materials. Beyond ammonium-ion storage, the strategies presented here open new avenues for multifunctional aqueous devices capable of simultaneously harvesting solar energy and storing ions.

Supercapacitor (SC), one of the most important classes of electrochemical energy storage devices, has attracted considerable attention due to their high power density, fast charging-discharging capabilities, superior cycling stability, and reliable performance. With the rapid advancement of portable and wearable electronics, the demand for high-performance flexible SCs has significantly intensified, thereby driving extensive research into advanced electrode materials, electrolytes, and device architecture. Among them, the development of electrode materials plays a decisive role in determining both electrochemical performance and mechanical flexibility of SCs. Herein, three electrode systems were designed and fabricated in this thesis: flexible diamond cloth (DC), NiMnOx-coated carbon cloth (NiMnOx@CC), and NiMnOx-coated diamond cloth (NiMnOx@DC). Their electrochemical performance was further and comprehensively evaluated by means of various techniques and tools. More details ae demonstrated as follows. The flexible DC was synthesized through the overgrowth of a boron-doped diamond (BDD) film on CC in a microwave plasma enhanced chemical vapor deposition (MWCVD) reactor. A Ti interlayer was first introduced to protect CC from plasma etching while simultaneously enhancing BDD adhesion. The DC electrode demonstrated excellent electrochemical performance, including enhanced capacitance, good rate performance, and exceptional cycling stability. A symmetric pseudocapacitor (PC) assembled from two DC electrodes delivered an energy density of 45.96 µWh cm-2 at a power density of 4.25 mW cm-2, retaining 17.64 µWh cm-2 at 67.93 mW cm-2. Moreover, the symmetric DC electric double-layer capacitor (EDLC) exhibited excellent mechanical flexibility. Pseudocapacitance was then introduced by electrochemical synthesis of Mn-oxide films on CC. This NiMnOx@CC electrode offered better conformality, thickness control, and reproducibility compared with electrodes prepared through hydrothermal methods. The optimized Ni-doped electrode exhibited larger current responses, a wide potential window (1.5 V), and distinct redox peaks, yielding a specific capacitance of 47.1 mF cm-2 at a scan rate of 10 mV s-1 and 42.8 mF cm-2 at a current density of 1 mA cm-2 in 1.0 M Na2SO4, with > 98.5 % coulombic efficiency over 10,000 cycles. Its cycling retention was limited (≈ 16% after 10,000 cycles), constraining practical application. CC was further replaced with DC as the substrate to produce a more stable NiMnOx@DC electrode. The optimal deposition potential of 1.0 V balanced deposition rate and side reactions. The as-fabricated NiMnOx@DC electrode exhibited pronounced redox features and high specific capacitances of 180.5 mF cm-2 at a scan rate of 10 mV s-1 and 228.1 mF cm-2 at a current density of 2 mA cm-2, coupled with exceptional coulombic efficiency approaching 100 % over 10,000 charging-discharging cycles. Furthermore, the NiMnOx@DC electrode exhibited significantly enhanced capacitance retention in comparison to the NiMnOx@CC electrode. The maximum energy density of 72.8 μWh cm-2 and maximum power density of 17.0 mW cm-2 were obtained for a symmetric NiMnOx@DC PC. Simultaneously, the quasi-solid-state device using the NiMnOx@DC electrodes showed excellent mechanical flexibility during the bending tests. In summary, this thesis presents a systematic and stepwise route to design different SC electrodes from DC to NiMnOx@DC, effectively integrating the advantages of CC, BDD, and Ni–Mn oxides. This strategy enables the fabrication of high-performance flexible SCs, which exhibit not only high energy density and rapid power delivery but also excellent long-term stability and mechanical flexibility. These advancements in electrode materials significantly contribute to the realization of practical applications for flexible SCs in portable and wearable electronic devices.

The Standard Model of Particle Physics (SM) is one of the most successful theories, describing the interactions of the fundamental building blocks of nature. However, a number of questions remain unanswered and require the exploration of physics beyond the SM. Aside from some fundamental problems like dark matter and dark energy, there are also small tensions in the data on flavour physics processes, indicating that physics beyond the SM must exist. Flavour physics, and in particular heavy quark physics, involve a broad range of theoretical methods, including tools to estimate or even compute non-perturbative quantities. The focus of this thesis lies on the application of non-perturbative methods for heavy quark systems. This will be exemplified by describing three projects. First, we discuss the treatment of quark masses within the heavy quark expansion and effective field theory. This framework provides powerful predictions for inclusive heavy hadron decays where the treatment of the quark mass plays a crucial role. Since the quark mass itself is not a physical observable, several short-distance mass schemes have been developed to minimize uncertainties induced by the quark mass. We suggest replacing the quark mass directly with an observable. Then we switch to another method by studying the exclusive decay process B → pΨ, observed as a proton and missing energy in the final state indicating the presence of a dark antibaryon Ψ. We determine the decay width using the QCD light-cone sum rule framework. In order to parameterize the non-perturbative effects in the operator product expansion, we systematically include all contributions up to twist six in the nucleon distribution amplitudes. Finally, we apply lattice QCD to a non-perturbative study of the exclusive Bs → Ds* ℓ νℓ decay parameterized by four form factors. Such b → c quark decays are of great phenomenological interest because they allow extraction of the CKM matrix element |Vcb| or testing of lepton flavour universality. We use ratios of two-point over three-point correlation functions evaluated on RBC/UKQCD’s set of 2+1 flavour gauge field ensembles. Following renormalization and extrapolation to the physical charm mass, we present a preliminary chiral-continuum fit in the simulated q² region.

The Gothic and its relation to boundaries is the focal point of this paper. The genre’s fluid and deconstructive character renders it uniquely apt for the study of historical gender relations. Attending to the fears and desires encoded in these narratives exposes the underlying power dynamics, as well as the gendered expectations and transgressive possibilities they contain.This thesis addresses the question of whether shifts can be discerned in Gothic literature across different historical periods, beginning with the eighteenth century. By examining the ideals and “monsters” that emerge in specific eras, it seeks to reveal the extent to which associated gender constructions are subject to historical variation and transformation. This study is organized into three parts, each dealing with its own specific time period and thematic cluster. It contains in-depth analyses of Gothic classics such as "A Sicilian Romance", "Jane Eyre", "Rebecca", "Dracula", "Interview with the Vampire", "Frankenstein", as well as their modern adaptations: Addie Tsai's "Unwieldy Creatures", Sarah Maria Griffin's "Spare and Found Parts", and Elizabeth Kostova's "The Historian".