Optically Sintered 2D RuO2 Nanosheets: Temperature‐Controlled NO2 Reaction

2D Ru oxide nanosheets (NSs) with optically punched nanoholes are synthesized and integrated on a flexible heating substrate, i.e., silver nanowire (Ag NW)‐embedded colorless polyimide (cPI) film, for application in wearable chemical sensors. Multiple discrete pores on the sub‐5‐nm scale are formed on the basal planes of Ru oxide NSs by irradiation of intense pulsed light. The chemical sensing characteristic of the porous Ru oxide NSs toward nitrogen dioxide (NO₂) is investigated under controlled temperatures by applying DC voltage to the Ag NW‐embedded cPI film. The improved NO₂ responding and recovery kinetics are achieved using the porous Ru oxide NSs with sensitivity of 1.124% at 20 ppm at a film temperature of 80.3 °C. A wireless patch‐type sensor module is developed to demonstrate wearable sensing of NO₂ using the Ru oxide NSs on Ag NW‐embedded cPI heating film. This work paved the new way for application of atomically thin and porous Ru oxide NSs in chemical sensors, which can detect hazardous species in real time.     

Electrical and gas sensing properties of <Emphasis Type="Italic">por</Emphasis>-Si/SnO<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> nanocomposite layers

The electrical characteristics and chemical reactant sensitivity of layers of heterogeneous nanocomposites based on porous silicon and nonstoichiometric tin oxide por-Si/SnO _x , fabricated by the magnetron sputtering of tin with subsequent oxidation, are studied. It is shown that, in the nanocomposite layers, a system of distributed heterojunctions (Si/SnO _x nanocrystals) forms, which determine the electrical characteristics of such structures. The sensitivity of test sensor structures based on por-Si/SnO _x nanocomposites to NO₂ is determined. A mechanism for the effect of the adsorption of NO₂ molecules on the current-voltage characteristics of the por-Si(p)/SnO _x (n) heterojunctions is suggested.     

A General Synthesis of Crumpled Metal Oxide Nanosheets as Superior Chemiresistive Sensing Layers

Metal oxide nanosheets having high mesoporosity, grain size distribution of 5–10 nm, and ultrathin thickness have attracted much attention due to their intriguing properties such as high surface‐to‐volume ratio and superior chemical activities. However, 2D nanostructures tend to restack, inducing a decrease in accessible surface area and a number of pores. To solve this problem, herein, a unique synthetic method of crumpled metal oxide nanosheets using spray pyrolysis of metal ion–coated graphene oxide, followed by heat treatment, is reported. This method is applicable not only to single‐component metal oxides but also to heterogeneous multicomponent metal oxides in which composition can be controlled. Crumpled SnO₂, ZnO, and Co₃O₄ as well as SnO₂/ZnO and SnO₂/Co₃O₄ nanosheets with heterogeneous interfaces are successfully synthesized and used as superior gas sensing layers. Because of the abundant reaction sites, well‐developed porosity for high gas accessibility, the formation of heterojunctions, the crumpled SnO₂/ZnO and SnO₂/Co₃O₄ nanosheets exhibit outstanding sensing performance (R_air/R_gas = 20.25 toward 5 ppm formaldehyde, and R_air/R_gas = 14.13 toward 5 ppm acetone, respectively). This study can contribute to the realization of a family of heterogeneous crumpled metal oxide nanosheets that can be applied to various research fields.     

Modeling the Metal–Insulator Phase Transition in LixCoO2 for Energy and Information Storage

An electro‐chemomechanical phase‐field model is developed to capture the metal–insulator phase transformation along with the structural and chemical changes that occur in Li_xCoO₂ in the regular operating range of 0.5 < x < 1. Under equilibrium, in the regime of phase coexistence, it is found that transport limitations lead to kinetically arrested states that are not determined by strain‐energy minimization. Further, lithiation profiles are obtained for different discharging rates and the experimentally observed voltage plateau is observed. Finally, a simple model is developed to account for the conductivity changes for a polycrystalline Li_xCoO₂ thin film as it transforms from the metallic phase to the insulating phase and a strategy is outlined for memristor design. The theory can therefore be used for modeling Li_xCoO₂‐electrode batteries as well as low voltage nonvolatile redox transistors for neuromorphic computing architectures.     

Safe‐by‐Design Exfoliation of Niobium Diselenide Atomic Crystals as a Theory‐Oriented 2D Nanoagent from Anti‐Inflammation to Antitumor

The accompanying relationship between tumor and inflammation raises the concept of concurrent antitumor and anti‐inflammation treatment in the clinic. Despite the wide application of 2D atomic crystals for cancer theranostics, their anti‐inflammation function has been rarely explored. Herein, it is reported that niobium diselenide nanosheets (NbSe₂ NSs), a “star” 2D superconducting atomic crystal, can serve as a theory‐oriented 2D nanoagent from anti‐inflammation to antitumor. A safe‐by‐design exfoliation strategy, integration of cryo‐pretreatment and DNA‐assisted exfoliation, is proposed for high‐efficiency exfoliation of atomically thin NbSe₂ NSs. Especially, computational simulation reveals that NbSe₂ NSs effectively eliminate reactive oxygen and nitrogen species (RONS) via hydrogen atom transfer and redox reaction. Upon the injection of NbSe₂ NSs into BALB/c mice, not only U87 subcutaneous tumors are rapidly ablated after photoacoustic imaging‐guided precise localization of tumor contour, but also lipopolysaccharide‐induced rear thigh inflammation or photothermal therapy‐mediated inflammation is efficiently inhibited through RONS scavenging. In addition, NbSe₂ NSs are highly biocompatible both in vitro and in vivo due to high‐security element constituent and DNA modification. The work extends the biomedical application of 2D atomic crystals for anti‐inflammatory treatment.     

Atomic‐Scale CoOx Species in Metal–Organic Frameworks for Oxygen Evolution Reaction

The activity of electrocatalysts strongly depends on the number of active sites, which can be increased by downsizing electrocatalysts. Single‐atom catalysts have attracted special attention due to atomic‐scale active sites. However, it is a huge challenge to obtain atomic‐scale CoO_x catalysts. The Co‐based metal–organic frameworks (MOFs) own atomically dispersed Co ions, which motivates to design a possible pathway to partially on‐site transform these Co ions to active atomic‐scale CoO_x species, while reserving the highly porous features of MOFs. In this work, for the first time, the targeted on‐site formation of atomic‐scale CoO_x species is realized in ZIF‐67 by O₂ plasma. The abundant pores in ZIF‐67 provide channels for O₂ plasma to activate the Co ions in MOFs to on‐site produce atomic‐scale CoO_x species, which act as the active sites to catalyze the oxygen evolution reaction with an even better activity than RuO₂.     

Heterostructured Visible‐Light‐Active Photocatalyst of Chromia‐Nanoparticle‐Layered Titanate

An efficient visible‐light active photocatalyst of porous CrO_x–Ti_1.83O₄ nanohybrid with a 1:1 type ordered heterostructure is synthesized through a hybridization between a chromia cluster and exfoliated titanate nanosheets. The present nanohybrids are found to have a large surface area (ca. 250–310 m² g^–1) and an intense absorption of visible light, ascribable, respectively, to the formation of a porous structure and the hybridization of titanate with narrow‐bandgap chromium oxide. After the calcination at 400 °C, the nanohybrid shows an enhanced photocatalytic activity to effectively decompose organic compounds under the irradiation of visible light (λ > 420 nm). The present study highlights the exfoliation–restacking route as a very powerful way to develop efficient visible‐light‐harvesting photocatalysts with excellent thermal stability.     

Thin‐Wall Assembled SnO2 Fibers Functionalized by Catalytic Pt Nanoparticles and their Superior Exhaled‐Breath‐Sensing Properties for the Diagnosis of Diabetes

Hierarchical SnO₂ fibers assembled from wrinkled thin tubes are synthesized by controlling the microphase separation between tin precursors and polymers, by varying flow rates during electrospinning and a subsequent heat treatment. The inner and outer SnO₂ tubes have a number of elongated open pores ranging from 10 nm to 500 nm in length along the fiber direction, enabling fast transport of gas molecules to the entire thin‐walled sensing layers. These features admit exhaled gases such as acetone and toluene, which are markers used for the diagnosis of diabetes and lung cancer. The open tubular structures facilitated the uniform coating of catalytic Pt nanoparticles onto the inner SnO₂ layers. Highly porous SnO₂ fibers synthesized at a high flow rate show five‐fold higher acetone responses than densely packed SnO₂ fibers synthesized at a low flow rate. Interestingly, thin‐wall assembled SnO₂ fibers functionalized by Pt particles exhibit a dramatically shortened gas response time compared to that of un‐doped SnO₂ fibers, even at low acetone concentrations. Moreover, Pt‐decorated SnO₂ fibers significantly enhance toluene response. These results demonstrate the novel and practical feasibility of thin‐wall assembled metal oxide based breath sensors for the accurate diagnosis of diabetes and potential detection of lung cancer.     

Enhanced photocatalytic activity of graphene oxide/titania nanosheets composites for methylene blue degradation

In the present work, we report enhanced photocatalytic degradation of methylene blue dye in aqueous solution by using ultra-thin anatase TiO₂ nanosheets (NSs) combined with graphene oxide (GO) as a photocatalyst. The two-dimensional ultra-thin anatase TiO₂ NSs are fabricated via chemical exfoliation. By completely delaminating a lepidocrocite-type layered protonic titanate H_xTi_2−x/4□_x/4O₄·H₂O (x=0.7, □: vacancy) into individual layers through ion exchange with tetrabutylammonium (TBA⁺) cations, well-dispersed ultra-thin colloidal Ti_0.91O₂ NSs with a lateral size up to a few micrometers are obtained. Subsequent acid treatment induces colloidal Ti_0.91O₂ to reassemble and precipitate into a gelation form, followed by thermal annealing to convert the Ti_0.91O₂ gelation into anatase TiO₂ nanosheets as photocatalyst for methylene blue degradation. TiO₂ NSs show a high photocatalytic degradation efficiency of 53.2% due to the ultra-thin thickness for facile electron transfering and large surface area for methylene blue absorption. Moreover, photocatalytic effect can be further improved by simply adding GO suspension to achieve colloidal self-assembly of GO and TiO₂ NSs. An optimal GO content of 3 wt% further increases the photocatalytic degradation efficiency to 91.2% due to faster electron–hole seperation and improved surface area provided by GO. This work provides a simple but effective approach by combing graphene oxide with TiO₂ nanosheets synthesized via the exfoliation method for methylene blue degradation.     

Rational Design of Highly Porous SnO2 Nanotubes Functionalized with Biomimetic Nanocatalysts for Direct Observation of Simulated Diabetes

1D metal‐oxide nanotube (NT) structures have attracted considerable attention for applications in chemical sensors due to their high surface area and unique chemical and physical properties. Moreover, bimodal pores, i.e., meso‐ and macro‐sized pores, which are formed on the shell of NTs, can further facilitate gas penetration into the sensing layers, leading to much improved sensing properties. However, thin‐walled NTs with bimodal pore distribution have been rarely fabricated due to the limitations of synthetic methods. Here, Ostwald ripening‐driven electrospinning combined with sacrificial templating route using polystyrene (PS) colloid and bioinspired protein is firstly proposed for producing both bi‐modal pores and catalyst‐loaded thin‐walled SnO₂ NTs. Homogeneous catalyst loading on porous SnO₂ NTs is achieved by the protein cage that contains catalysts and PS colloids and protein shells are thermally decomposed during calcination of electrospun fibers, resulting in the creation of dual‐sized pores on NTs. Pt catalyst decorated porous SnO₂ NTs (Pt‐PS_SnO₂ NTs) show exceptionally high acetone gas response, superior selectivity against other interfering gases, and very low limit of detection (10 ppb) to simulated diabetic acetone molecules. More importantly, sensor arrays assembled with developed porous SnO₂ NTs enable the direct distinction between the simulated diabetic breath and normal breath from healthy people.     

Degenerately Hydrogen Doped Molybdenum Oxide Nanodisks for Ultrasensitive Plasmonic Biosensing

Plasmonic biosensors based on noble metals generally suffer from low sensitivities if the perturbation of refractive‐index in the ambient is not significant. By contrast, the features of degenerately doped semiconductors offer new dimensions for plasmonic biosensing, by allowing charge‐based detection. Here, this concept is demonstrated in plasmonic hydrogen doped molybdenum oxides (H_xMoO₃), with the morphology of 2D nanodisks, using a representative enzymatic glucose sensing model. Based on the ultrahigh capacity of the molybdenum oxide nanodisks for accommodating H⁺, the plasmon resonance wavelengths of H_xMoO₃ are shifted into visible‐near‐infrared wavelengths. These plasmonic features alter significantly as a function of the intercalated H⁺ concentration. The facile H⁺ deintercalation out of H_xMoO₃ provides an exceptional sensitivity and fast kinetics to charge perturbations during enzymatic oxidation. The optimum sensing response is found at H_1.55MoO₃, achieving a detection limit of 2 × 10^?9m at 410 nm, even when the biosensing platform is adapted into a light‐emitting diode‐photodetector setup. The performance is superior in comparison to all previously reported plasmonic enzymatic glucose sensors, providing a great opportunity in developing high performance biosensors.     

Gas Sensors: Ultrasensitive and Highly Selective Gas Sensors Based on Electrospun SnO2 Nanofibers Modified by Pd Loading (Adv. Funct. Mater. 24/2010)

This work presents a new route to suppress grain growth and tune the sensitivity and selectivity of nanocrystalline SnO₂ fibers. Unloaded and Pd‐loaded SnO₂ nanofiber mats are synthesized by electrospinning followed by hot‐pressing at 80 °C and calcination at 450 or 600 °C. The chemical composition and microstructure evolution as a function of Pd‐loading and calcination temperature are examined using EDS, XPS, XRD, SEM, and HRTEM. Highly porous fibrillar morphology with nanocrystalline fibers comprising SnO₂ crystallites decorated with tiny PdO crystallites is observed. The grain size of the SnO₂ crystallites in the layers that are calcined at 600 °C decreases with increasing Pd concentration from about 15 nm in the unloaded specimen to about 7 nm in the 40 mol% Pd‐loaded specimen, indicating that Pd‐loading could effectively suppress the SnO₂ grain growth during the calcination step. The Pd‐loaded SnO₂ sensors have 4 orders of magnitude higher resistivity and exhibit significantly enhanced sensitivity to H₂ and lower sensitivity to NO₂ compared to their unloaded counterparts. These observations are attributed to enhanced electron depletion at the surface of the PdO‐decorated SnO₂ crystallites and catalytic effect of PdO in promoting the oxidation of H₂ into H₂O. These phenomena appear to have a much larger effect on the sensitivity of the Pd‐loaded sensors than the reduction in grain size.     

Ultrasensitive and Highly Selective Gas Sensors Based on Electrospun SnO2 Nanofibers Modified by Pd Loading

This work presents a new route to suppress grain growth and tune the sensitivity and selectivity of nanocrystalline SnO₂ fibers. Unloaded and Pd‐loaded SnO₂ nanofiber mats are synthesized by electrospinning followed by hot‐pressing at 80 °C and calcination at 450 or 600 °C. The chemical composition and microstructure evolution as a function of Pd‐loading and calcination temperature are examined using EDS, XPS, XRD, SEM, and HRTEM. Highly porous fibrillar morphology with nanocrystalline fibers comprising SnO₂ crystallites decorated with tiny PdO crystallites is observed. The grain size of the SnO₂ crystallites in the layers that are calcined at 600 °C decreases with increasing Pd concentration from about 15 nm in the unloaded specimen to about 7 nm in the 40 mol% Pd‐loaded specimen, indicating that Pd‐loading could effectively suppress the SnO₂ grain growth during the calcination step. The Pd‐loaded SnO₂ sensors have 4 orders of magnitude higher resistivity and exhibit significantly enhanced sensitivity to H₂ and lower sensitivity to NO₂ compared to their unloaded counterparts. These observations are attributed to enhanced electron depletion at the surface of the PdO‐decorated SnO₂ crystallites and catalytic effect of PdO in promoting the oxidation of H₂ into H₂O. These phenomena appear to have a much larger effect on the sensitivity of the Pd‐loaded sensors than the reduction in grain size.     

Amorphous Zinc Stannate (Zn2SnO4) Nanofibers Networks as Photoelectrodes for Organic Dye‐Sensitized Solar Cells

A new strategy for developing dye‐sensitised solar cells (DSSCs) by combining thin porous zinc tin oxide (Zn₂SnO₄) fiber‐based photoelectrodes with purely organic sensitizers is presented. The preparation of highly porous Zn₂SnO₄ electrodes, which show high specific surface area up to 124 m²/g using electrospinning techniques, is reported. The synthesis of a new organic donor‐conjugate‐acceptor (D‐π‐A) structured orange organic dye with molar extinction coefficient of 44 600 M^?1 cm^?1 is also presented. This dye and two other reference dyes, one organic and a ruthenium complex, are employed for the fabrication of Zn₂SnO₄ fiber‐based DSSCs. Remarkably, organic dye‐sensitized DSSCs displayed significantly improved performance compared to the ruthenium complex sensitized DSSCs. The devices based on a 3 μm‐thick Zn₂SnO₄ electrode using the new sensitizer in conjunction with a liquid electrolyte show promising photovoltaic conversion up to 3.7% under standard AM 1.5G sunlight (100 mW cm^?2). This result ranks among the highest reported for devices using ternary metal oxide electrodes.     

Controllably Engineering Mesoporous Surface and Dimensionality of SnO2 toward High‐Performance CO2 Electroreduction

Currently, the precise control of the architecture and surface of functional materials for high‐performance still remains a great challenge. Here, a feasible approach is presented to synchronously manipulate mesoporous surface and dimensionality of SnO₂ catalysts into hierarchically mesoporous nanosheets and nanospheres within one simple reaction system. By adjustment of the hydrophobic chain length of different fluorinated surfactants, 0D SnO₂ nanospheres with average size of 165 nm, and 2D SnO₂ ulthrathin nanosheets with thickness of 22.5 nm with the distinct dimensionalities are separately obtained (one stone, two birds), both of which are well decorated with ordered mesopore arrays on their surfaces (pore size of 16 nm). The following calcination gave rise to the formation of hierarchically mesopores (5 and 16 nm, respectively) with high crystallization and improved surface area (96.8 m² g^?1). The resultant mesoporous SnO₂ nanosheets as catalyst for CO₂ electroreduction reaction (CO₂ RR) exhibit excellent selectivity, with a high Faraday efficiency (FE) of HCOOH reaching up to 90.0% at ?1.3 V and C₁ FE of 97.4% at ?1.2 V versus reversible hydrogen electrode, as well as long‐term stability, which is among the best performance compared to reported SnO₂ materials, thanks to the collective contributions of the unique architecture and mesoporous structure.     

Optical generation of free charge carriers in thin films of tin oxide

The methods of infrared absorption spectroscopy and Raman spectroscopy are used to study nanocrystalline SnO _x films (1 ≤ x ≤ 2) prepared by thermal oxidation of metallic tin layers. A monotonic decrease in the transmittance of films in the infrared region has been observed as a result of exposure of the films to light with the wavelength of 380 nm at room temperature. The effect is at a maximum for the samples with x ≈ 2 and is observed for ∼10 min after switching off of illumination. The mentioned variations in optical properties, similarly to those observed in the case of heating of the samples in the dark, are accounted for by an increase in the concentration of free charge carriers (electrons) in nanocrystals of tin dioxide. The data of infrared spectroscopy and the Drude model are used to calculate the concentrations of photogenerated charge carriers (∼10¹⁹ cm⁻³); variations in these concentrations in the course of illumination and after switching off of illumination are determined. Mechanisms of observed photogeneration of charge carriers in SnO _x films and possible applications of this effect to gas sensors are discussed.     

SnTe@MnO2‐SP Nanosheet–Based Intelligent Nanoplatform for Second Near‐Infrared Light–Mediated Cancer Theranostics

Near infrared light, especially the second near‐infrared light (NIR II) biowindows with deep penetration and high sensitivity are widely used for optical diagnosis and phototherapy. Here, a novel kind of 2D SnTe@MnO₂‐SP nanosheet (NS)‐based nanoplatform is developed for cancer theranostics with NIR II‐mediated precise optical imaging and effective photothermal ablation of mouse xenografted tumors. The 2D SnTe@MnO₂‐SP NSs are fabricated via a facile method combining ball‐milling and liquid exfoliation for synthesis of SnTe NSs, and surface coating MnO₂ shell and soybean phospholipid (SP). The ultrathin SnTe@MnO₂‐SP NSs reveal notably high photothermal conversion efficiency (38.2% in NIR I and 43.9% in NIR II). The SnTe@MnO₂‐SP NSs inherently feature tumor microenvironment (TME)‐responsive biodegradability, and the main metabolite TeO₃^2? shows great antitumor effect, coupling synergetic chemotherapy for cancer. Moreover, the SnTe@MnO₂‐SP NSs also exhibit great potential for fluorescence, photoacoustic (PA), and photothermal imaging agents in the NIR II biowindow with much higher resolution and sensitivity. This is the first report, as far as is known, with such an inorganic nanoagent setting fluorescence/PA/photothermal imaging and photothermal therapy in NIR II biowindow and TME‐responsive biodegradability rolled into one, which provide insight into the clinical potential for cancer theranostics.     

Self-Standing 3D Hollow Nanoporous SnO2-Modified CuxO Nanotubes with Nanolamellar Metallic Cu Inwalls: A Facile In Situ Synthesis Protocol toward Enhanced Li Storage Properties

SnO₂ is regarded as a prospective anode material candidate for high energy density lithium-ion batteries (LIBs). However, rapid structural degradation and low conductivity always bring about poor cycling stability and electrochemical reversibility, becoming critical dilemmas toward its practical application. To address these issues, herein, a facile multi-step in situ synthesis protocol is developed to tactfully achieve self-standing 3D hollow nanoporous SnO₂-modified Cu_xO nanotubes with nanolamellar metallic Cu inwalls (3D-HNP SnO₂/Cu_xO@n-Cu) via chemical dealloying, heat treatment, electrochemical replacement, and selective etching. The results show that the unique 3D-HNP SnO₂/Cu_xO@n-Cu as a binder-free integrated anode for LIBs exhibits superior Li storage properties with high initial reversible capacity of 3.34 mAh cm⁻² and good cycling stability with 85.6% capacity retention and >99.4% coulombic efficiency after 200 cycles (capacity decay of only 0.002 mAh cm⁻² per cycle). This is mainly attributed to the unique 3D hollow nanoporous configuration design composed of interlinked Cu_xO nanotubes modified by ultrafine SnO₂ nanocrystals (4–10 nm) with two-way mechanical strain cushion and nanolamellar metallic Cu inwalls with boosted electrical conductivity. This work can be expected to offer an original and effective approach for rational design and fabrication of advanced MOx-based anodes toward high-performance LIBs.     

Efficient OER Catalyst with Low Ir Volume Density Obtained by Homogeneous Deposition of Iridium Oxide Nanoparticles on Macroporous Antimony‐Doped Tin Oxide Support

A multistep synthesis procedure for the homogeneous coating of a complex porous conductive oxide with small Ir nanoparticles is introduced to obtain a highly active electrocatalyst for water oxidation. At first, inverse opal macroporous Sb doped SnO₂ (ATO) microparticles with defined pore size, composition, and open‐porous morphology are synthesized that reach a conductivity of ≈3.6 S cm^?1 and are further used as catalyst support. ATO‐supported iridium catalysts with a controlled amount of active material are prepared by solvothermal reduction of an IrO_x colloid in the presence of the porous ATO particles, whereby homogeneous coating of the complete outer and inner surface of the particles with nanodispersed metallic Ir is achieved. Thermal oxidation leads to the formation of ATO‐supported IrO₂ nanoparticles with a void volume fraction of ≈89% calculated for catalyst thin films based on scanning transmission electron microscope tomography data and microparticle size distribution. A remarkably low Ir bulk density of ≈0.08 g cm^?3 for this supported oxide catalyst architecture with 25 wt% Ir is determined. This highly efficient oxygen evolution reaction catalyst reaches a current density of 63 A g_Ir^?1 at an overpotential of 300 mV versus reversible hydrogen electrode, significantly exceeding a commercial TiO₂‐supported IrO₂ reference catalyst under the same measurement conditions.     

Light Enhanced Electron Transduction and Amplified Sensing at a Nanostructure Modified Semiconductor Interface

Visible and UV light are demonstrated to significantly enhance the sensing properties of an n‐type porous silicon (PS) extrinsic semiconductor interface to which TiO₂ and titanium oxynitride (TiO_2‐xN_x) photocatalytic nanostructures are fractionally deposited. The acid/base chemistry of NH₃, a moderately strong base, and NO₂, a moderately strong acid, couples to the majority charge carriers of the doped semiconductor as the strong acid (TiO₂) enhances the extraction of electrons from NH₃, and the more basic TiO_2‐xN_x decreases the efficiency of electron extraction relative to the untreated interface. In contrast, NO₂ and a TiO₂ or TiO_2‐xN_x nanostructure‐decorated PS interface compete for the available electrons leading to a distinct time dependent electron transduction dynamics as a function of TiO₂ and TiO_2‐xN_x concentration. Only small concentrations of TiO₂ and its oxynitride and no self‐assembly are required to enhance the response of the decorated interface. With light intensities of less than a few lumens/cm²‐sterad‐nm, responses are enhanced by up to 150% through interaction with visible (and UV) radiation. These light intensities should be compared to the sun's radiation level, ≈500 lumens/cm²‐sterad‐nm suggesting the possibility of solar pumped sensors. The observed behavior in these systems is largely explained by the recently developed Inverse Hard/Soft Acid/Base (IHSAB) concept.