Solvothermal Microwave Research Articles

Photocatalytic Degradation of Transition Metal (Ni) Doped ZnS Nanoparticles Synthesized via Simple Solvothermal Route

Ni doped ZnS nanoparticles were obtained using the simple Solvothermal Microwave Irradiation (SMI) method in this research. This technique is cost-effective and results in a high level of uniformity in particle size. The sample's structural characteristics were examined utilizing XRD Technique, FESEM image, Elemental analysis of the as prepared sample obtained from EDX spectrum and their optical characteristics analysed by using UV-Visible absorption study. The XRD pattern of Ni doped ZnS nanoparticles were to obtain their crystallite size (D), lattice constant (a), and volume of the unit cell (V). As the concentration of Ni dopant increased (0, 2.5, 5.0) M %, the values of the lattice constant decreased, leading to an overall decrease in the volume of the unit cell. FESEM images reveals the sample have uniform surface morphology and EDX analysis give evidence for element Zn, Ni, S presents in the sample. Ni doped ZnS nanoparticle dimension strongly influences their optical characteristics. The optical bandgap, as obtained from UV-Vis measurements, ranges from 3.54 eV to 3.50 eV with doping concentrations varying from 0 M% to 5.0 M% .This adjustment in optical properties suggests that Ni-doped ZnS nanoparticles have diverse applications in optoelectronics, sensors, UV detectors, and as an efficient photocatalyst for degrading pollutants in water. The efficiency of the degradation of Methylene Blue dye by Ni doped ZnS nanoparticles was found to be 75.19%.

Facile Synthesis and Characterization of Pure and Bi-doped ZnS Nanoparticles for Photocatalytic Application

In the present research, a simple solvothermal microwave irradiation (SMI) method has been adopted for the preparation and synthesis of pure and Bi doped ZnS nanoparticles using zinc acetate, bismuth acetate, thiourea and ethylene glycol were utilized as precursors. As-synthesized pure and Bi doped ZnS nanoparticles were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDAX), ultraviolet-visible (UV-vis) spectroscopy and Field emission scanning electron microscopy (FESEM). From the XRD and EDAX studies, crystallite size, lattice parameter and analysis of the elemental compositions are calculated and analyzed respectively. The UV-vis spectra revealed that the optical band gap energy of pure and Bi doped ZnS nanoparticles was calculated. The FESEM shows that the average particle size spherical and agglomerated of as-synthesized pure and Bi doped ZnS nanoparticles sizes were decreased. In addition, the photocatalytic activity of pure and Bi doped ZnS nanoparticles was studied with methylene blue dye in an aqueous solution under UV light irradiation; the 5.0 mol % of Bi doped ZnS nanoparticles dye degradation efficiency of the sample was calculated as 75% in 120 minutes.

Coupling high entropy oxide with hollow carbon spheres by rapid microwave solvothermal strategy for boosting oxygen evolution reaction

High entropy oxides (HEOs) are promising oxygen evolution electrocatalysts due to the unique structure, inherent tunability, as well as excellent catalytic activity and stability. Herein, (FeCoNiCrMn)3O4 nanoparticles coupling with the hollow-mesoporous carbon spheres (HCS) has been designed and fabricated by a rapid and efficient microwave solvothermal followed by annealing. The prepared (FeCoNiCrMn)3O4 nanoparticles are highly dispersed on the HCS surface with an average particle size of approximately 3.3 nm. The composite with large surface areas can facilitate mass transfer and gas release, and it allows more active sites to be exposed. The obtained (FeCoNiCrMn)3O4/hollow-mesoporous carbon sphere composite catalyst with the optimal HEO load (HEO/HCS-3) exhibits outstanding oxygen evolution reaction (OER) electrocatalytic performance with a low overpotential of 263 mV at 10 mA cm−2, and a small Tafel slope of 41.24 mV dec−1, better than the pure (FeCoNiCrMn)3O4 and commercial RuO2 catalyst. The long-term durability of HEO/HCS-3 is also achieved by continuous electrolysis in 1 M KOH solution for more than 100 h. The outstanding catalytic performance of the composite can be ascribed to the clever structural design and the well-matched synthetic method. This research can guide the construction of high-efficient OER catalysts.

Microwave solvothermal synthesis of Component-Tunable High-Entropy oxides as High-Efficient and stable electrocatalysts for oxygen evolution reaction

Transition-metal-based high-entropy oxides (HEOs) are appealing electrocatalysts for oxygen evolution reaction (OER) due to their unique structure, variable composition and electronic structure, outstanding electrocatalytic activity and stability. Herein, we propose a scalable high-efficiency microwave solvothermal strategy to fabricate HEO nano-catalysts with five earth-abundant metal elements (Fe, Co, Ni, Cr, and Mn) and tailor the component ratio to enhance the catalytic performance. (FeCoNi2CrMn)3O4 with a double Ni content exhibits the best electrocatalytic performance for OER, namely low overpotential (260 mV@10 mA cm−2), small Tafel slope and superb long-term durability without obvious potential change after 95 h in 1 M KOH. The extraordinary performance of (FeCoNi2CrMn)3O4 can be attributed to the large active surface area profiting from the nano structure, the optimized surface electronic state with high conductivity and suitable adsorption to intermediate benefitting from ingenious multiple-element synergistic effects, and the inherent structural stability of the high-entropy system. In addition, the obvious pH value dependable character and TMA+ inhibition phenomenon reveal that the lattice oxygen mediated mechanism (LOM) work together with adsorbate evolution mechanism (AEM) in the catalytic process of OER with the HEO catalyst. This strategy provides a new approach for the rapid synthesis of high-entropy oxide and inspires more rational designs of high-efficient electrocatalysts.

Efficient Synthesis of 2D Mica Nanosheets by Solvothermal and Microwave-Assisted Techniques for CO2 Capture Applications

Mica, a commonly occurring mineral, has significant potential for various applications due to its unique structure and properties. However, due to its non-Van Der Waals bonded structure, it is difficult to exfoliate mica into ultrathin nanosheets. In this work, we report a rapid solvothermal microwave synthesis of 2D mica with short reaction time and energy conservation. The resulting exfoliated 2D mica nanosheets (eMica nanosheets) were characterized by various techniques, and their ability to capture CO2 was tested by thermogravimetric analysis (TGA). Our results showed an 87% increase in CO2 adsorption capacity with eMica nanosheets compared to conventional mica. Further characterization by Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), as well as first-principles calculations, showed that the high specific surface area and deposited K2CO3 layer contribute to the increased CO2 adsorption on the mica nanosheets. These results speak to the potential of high-quality eMica nanosheets and efficient synthesis processes to open new avenues for new physical properties of 2D materials and the development of CO2 capture technologies.

Functional surface homogenization of nanobiochar with cation exchanger for improved removal performance of methylene blue and lead pollutants

Biochar materials are good examples of sustainable adsorbents with appreciable recent interests and applications in water treatment. The disadvantage of using unmodified pristine biochars in water treatment is mainly related to the inhomogeneous distribution of various surface functional groups. Therefore, the current study is designed to functionalize and homogenize the surface of a selected nanobiochar with a cation exchanger using hydrothermal and solvothermal microwave irradiation. The adsorption behavior of immobilized Amberlite cation exchanger onto Cynara scolymus nanobiochar (ACE@CSNB) was compared versus the pristine Cynara scolymus nanobiochar (CSNB). ACE@CSNB was categorized as a typical mesoporous material (mean pore size = 2.238 nm) and the FT-IR spectra confirmed surface modification via two characteristic peaks at 1140–1250 cm−1 and 1030–1070 cm−1 for R-SO3− with S = O. The TPD–MS analysis of CSNB and ACE@CSNB referred to the presence of carboxyl, lactonic, and acid anhydride groups as well as phenolic moieties. The adsorption behavior of methylene blue dye and lead ions by ACE@CSNB was found much higher than those concluded by CSNB providing maximum adsorptive capacity values owing to the played clear role by Amberlite cation exchanger. Moreover, ACE@CSNB was efficiently regenerated and confirmed MB and Pb(II) removal with 92.26% and 1000 µmol g−1, respectively Finally, the removal efficiency values from three water matrices by ACE@CSNB biochar were characterized as 91.74–98.19% and 96.27–99.14% for Pb(II) and MB, respectively to refer to the validity and applicability of the investigated ACE@CSNB biochar for treatment of these two pollutants from real water samples with excellent efficiency.Graphical

Improved Performance of the Al2O3-Protected HfO2-TiO2 Base Layer with a Self-Assembled CH3NH3PbI3 Heterostructure for Extremely Low Operating Voltage and Stable Filament Formation in Nonvolatile Resistive Switching Memory.

Herein, we report intriguing observations of an extremely stable nonvolatile bipolar resistive switching (NVBRS) memory device fabricated using HfO2-TiO2 topologically protected by Al2O3 as a stacked base layer for a CH3NH3PbI3 (MAPI) electrolyte layer sandwiched between Ag and fluorine-doped tin oxide (FTO) electrodes. MAPI has been successfully synthesized by a rapid microwave-solvothermal (MW-ST) method within 10 min at 120 °C without requiring any inert gas atmosphere using low-cost precursors and solvents. Subsequently, MAPI powders are dissolved in aprotic solvents (DMF/DMSO = 8:2), and a spin-coated thin film is allowed to recrystallize upon annealing at 120 °C via a solution-based nanoscale self-assembly process. The fabricated memory device with the Ag/MAPI/Al2O3/TiO2-HfO2/FTO configuration shows an enhanced resistance ratio of 105 for >104 s at an extremely lower operating voltage (SET +0.2 V, RESET -0.2 V) when compared to that of the pristine MAPI device (±1 V, 102, 104 s). We show that the memory device also exhibits a remarkable endurance of ≥3500 cycles due to the Al2O3 robust coating on the HfO2-TiO2 layer, facilitating prompt heterojunction formation. Thus, the adopted innovative strategies to prepare structurally and optically stable (∼1.5 years) MAPI under high-humid conditions could offer enhanced performance of NVBRS memory devices for medical, security, internet of things (IoT), and artificial intelligence (AI) applications.

A Heterogeneous Bifunctional Carbon Nanocatalyst from Plastic Waste to Efficiently Catalyze Waste Cooking Oil into Biodiesel

In this study, black carbon derived from polyethylene terephthalate (PET) wastes was utilized as the precursor for heterogeneous bifunctional nanocatalyst, which successively catalyzed waste cooking oil into biodiesel. The nano-sized catalysts were prepared by impregnation method with different heat treatment techniques, such as reflux, hydrothermal, and microwave solvothermal, to provide good distribution of K2O and NiO particles on PET activated carbon mesoporous surface. The sample treated with microwave solvothermal technique (MAC-K2O-NiO) exhibited a high surface area of 120 m2/g with good dispersion of nanoparticles, as shown by FESEM image, large crystallite size of 62.2 nm, and consisted of a highest density of basicity (2.58 mmol/g) and acidity (1.79 mmol/g) for improving transesterification to a maximum yield. The catalytic transesterification of MAC-K2O-NiO was optimized with 3 wt.% of catalyst loading, 18: 1 methanol-oil molar ratio, 65 °C for 3 h of reaction, with a maximum yield of 97.2%. The catalyst reusability was performed, and it was found to maintain the catalytic activity up to six reaction cycles, with a yield of 72.9%. The physiochemical quality of the optimized biodiesel was examined in accordance with the American Society for Testing and Materials, ASTM D6751 testing method.

Floating TiO2-Cork Nano-Photocatalysts for Water Purification Using Sunlight

In the present study, titanium dioxide (TiO2) nano-photocatalysts were synthesized through microwave irradiation. In a typical microwave synthesis, TiO2 nanomaterials were simultaneously produced in powder form and also directly covering cork substrates. The TiO2 nanopowder was analyzed by X-ray diffraction (XRD), Raman spectroscopy and transmission electron microscopy (TEM), revealing that the solvothermal microwave synthesis resulted only in the TiO2 anatase phase. From Fourier-transform infrared spectroscopy (FTIR), cork’s organic species, along with bands of TiO2, were detected. UV–VIS absorption spectrum revealed an absorption extension to the visible region, since a brown powdered TiO2 product was obtained. Very fine nanoparticles were observed displaying a nearly spherical shape that agglomerates in larger particles. These larger particles fully covered the surface of the honeycomb cork cells, originating TiO2 functionalized cork platforms. The TiO2 functionalized substrates were further tested as floating photocatalysts and their photocatalytic activity was assessed from rhodamine B degradation under solar simulating light and natural sunlight. Reusability tests were also performed under natural sunlight. The strategy applied in this research work allowed the production of green and low-cost cork platforms based on TiO2 photoactive materials with the ability to purify polluted water under natural sunlight.

Porous carbon materials derived from discarded COVID-19 masks via microwave solvothermal method for lithium‑sulfur batteries

With the spread of COVID-19, disposable medical masks (DMMs) have become a significant source of new hazardous solid waste. Their proper disposal is not only beneficial to the safety of biological systems but also useful to achieve considerable economic value. The first step of this study was to investigate the chemical composition of DMMs. It is primarily composed of polypropylene, polyethylene terephthalate and iron, with fibrous polypropylene accounting for approximately 80% of the total weight. Then, DMMs were sulfonated and oxidised by the microwave-driven concentrated sulfuric acid within 8 min based on the fact that the concentrated sulfuric acid exhibits a good microwave absorption capacity. The co-doping of sulfur and oxygen was achieved while improving the thermal stability of DMMs. Subsequently, the self-activation pyrolysis of sulfonated and oxidised DMMs (P-SO@DMMs) was further realized in low-flow-rate argon. The specific surface area of P-SO@DMMs increased from 2.0 to 830.9 m2·g−1. P-SO@DMMs sulfur cathodes have promising electrochemical properties because of their porous structures and the synergistic effect of sulfur and oxygen co-doping. The capacity of the samples irradiated by microwave for 10 min at 0.1, 0.2, 0.5, 1, 2 and 5 C were 1313.6, 1010.9, 816.5, 634.4, 513.4 and 453.1 mAh·g−1, respectively, and after returning to 0.2 C and continuing the cycle for 50 revolutions, maintained 50.5% of the initial capacity. After 400 cycles, its capacity is 38.1% of the initial capacity at 0.5 C. It is slightly higher than the electrochemical performance of the sample treated by microwave for 8 min and significantly higher than the sample treated by 6 min. This work converts structurally complex, biohazardous DMMs into porous carbon with high specific surface area by clean and efficient microwave solvothermal and self-activating pyrolysis, which facilitates the development of carbon based materials at low cost and large scale.

Facile synthesis of undoped and Sn doped CdS nanoparticles for dye-sensitized solar cell applications

Undoped and tin (Sn) doped cadmium sulfide (CdS) semiconductor alloy nanoparticles have been prepared by simple solvothermal microwave irradiation (SMI) technique. Powder X-ray diffraction (PXRD) analysis indicates the formation of hexagonal structured high-quality nanoparticles with crystallite size around 3 nm. The particle size of the samples obtained from transmission electron microscopy (TEM) analysis is in accordance with the crystallite size of prepared nanoparticles. The surface morphology examined using a field emission scanning electron microscope shows the uniform distribution of spherical nanoparticles. The energy dispersive X-ray (EDX) analysis confirms the purity of the prepared nanoparticles with a good stoichiometric ratio of Cd, S, and Sn. The optical characteristic of the samples by UV–Visible (UV–Vis.) analysis implies that the optical band gap tends to decrease for the increase in Sn concentration in CdS lattices. Dye-sensitized solar cell with 4 mol % Sn doped CdS nanoparticles shows ~39% higher efficiency than that of undoped CdS.

One-pot green extraction of high charge density cellulose nanocrystals with high yield for bionanocomposites

The use of lignocellulosic materials for extracting functionalized cellulose nanocrystals (FCNs) in a green and sustainable method under mild conditions is limited owing to the strong hydrogen bonding in cellulose. A facile, green, and high-efficient avenue was developed to produce FCNs with high yield through the mechanochemistry synergetic effect of recyclable p-toluenesulfonic acid (PTSA)-catalyzed deep eutectic solvent (PDES) and microwave- solvothermal (MWS). FCNs with a high charge density of 1.59 e nm−2, a crystallinity of 81%, a better thermostability and dispersibility were obtained at a high yield of 87.6% by the one-step processing. The PDES could be easily recycled, and thus was beneficial to cost reduction and waste liquor treatment. Generated FCNs could be used to develop functional bionanocomposites due to their enhanced effect. When a loading of 1 wt% FCNs was added into gelatin matrix, the tensile strength and Young’s modulus of the bionanocomposites increased 188 and 131%, respectively, suggesting their remarkable stress transfer potential. Thus, the study demonstrates a green and cost-effective approach for the mass production of FCNs, contributing to strong potential in building high-performance bionanocomposites.

Nature of Alkali Ion Conduction and Reversible Na-Ion Storage in Hybrid Formate Framework Materials

The cost advantage of Na-ion batteries has spurred intensive research effort in the last 10 years to develop reversible Na+ storage materials. Although classic host materials—analogous to those in the Li-ion system—are potentially straightforward targets, sluggish Na+ diffusion in many inorganic structures limits options. In this regard, open framework inorganic–organic hybrids such as metal–organic framework materials are considered as viable alternatives. Herein, we introduce heterometallic formate frameworks as potential candidates for reversible Na+ storage. As a first, we present a microwave solvothermal strategy for rapid synthesis of phase-pure microcrystalline Na2Co(HCO2)4 and AB(HCO2)3 (A: Li/Na; B: Co/Mn). By combining in-depth impedance analysis with ab initio molecular dynamics simulation, we reveal that the Li+/Na+ conduction—which follows a “pinball” mechanism—in these materials is extrinsic defect-dominated. Calculation suggests that a librational motion of the formate anions facilitates the diffusion of Na+ compared to Li+, explaining the origin of anomalously higher ionic conductivity for the Na analogue compared to the Li one. Preliminary electrochemical investigation reveals reversible Na+ storage in Na2Co(HCO2)4 and NaMn(HCO2)3 at an average voltage of 2.5–3 V.

Microwave Solvothermal Synthesis of Three-Dimensional Bi2MoO6 Microspheres with Enhanced Photocatalytic Activity.

In this study, three-dimensional (3D) Bi2MoO6 microspheres were successfully fabricated by a facile, rapid, and mild microwave solvothermal strategy for the first time. The resultant 3D Bi2MoO6 microspheres exhibited superior adsorption capacity and photocatalytic efficiency in the degradation of the representative antibiotic ciprofloxacin under visible light, for which the reaction kinetic rate constant is 7.5 times as high as that of the as-synthesized zero-dimensional Bi2MoO6 nanoparticles. The 3D hierarchical porous structure and the high Brunauer–Emmett–Teller surface area providing abundant reactive sites mainly contributed to the enhanced photocatalytic activity. The results highlight the feasibility of 3D Bi2MoO6 microspheres as an efficient visible-light-responsive photocatalyst for antibiotic removal in an aqueous system.

Microwave-Enhanced Chemistry at Solid-Liquid Interfaces: Synthesis of All-Inorganic CsPbX3 Nanocrystals and Unveiling the Anion-Induced Evolution of Structural and Optical Properties.

We demonstrate how microwaves could enhance the chemistry at interfaces of heterogeneous reactions involved in the microwave-solvothermal (MW-ST) synthesis of all-inorganic CsPbX3 (X = Cl, Br, I) perovskite nanocrystals (PNCs) within 6 min, unlike a conventional hot-injection method that requires 3 h. The enhanced MW-ST reaction rate was quantitatively analyzed by the Eyring equation, and it has been observed that the decreased activation free energy (ΔG⧧) and increased activation entropy (ΔS⧧) are caused by changes in the relative energies of reactants at their solid-liquid interfaces, leading to the formation of "hot spots", where microwave energy absorption is at its maximum. This rapid and homogeneous microwave heating could facilitate the self-assembly of uniformly distributed CsPbX3 nanocubes with precise control over the stoichiometric ratio, as confirmed by high-resolution transmission electron microscopy and energy-dispersive X-ray analyses. X-ray diffraction and Raman results indicate that lattice contraction and expansion in CsPbBr3-yXy have occurred because of an increase in the metal-halide bond length upon moving down the groups Cl → Br → I, as further ascertained by the Rietveld refinement studies. These anion-induced structural variations accordingly affected the electronic properties of MW-ST-synthesized CsPbX3 PNCs, which is apparent from the shifts in their conduction-band (CB) and valence-band (VB) positions. Consequently, the optical properties were also altered, resulting in a color-tuned emission from blue to red, with excellent photoluminescence quantum yields (up to 92%) and narrow emission line widths, as is evident from UV-vis and photoluminescence spectroscopy. The MW-ST-synthesized CsPbX3 PNCs were used as color-conversion layers for the fabrication of light-emitting diodes (LEDs) with commercial 456 nm UV-LED chips.

Synthesis of magnesium-doped TiO2 photoelectrodes for dye-sensitized solar cell applications by solvothermal microwave irradiation method

Abstract

Ultrafast synthesis of Mn0.8Co0.2CO3/graphene composite as anode material by microwave solvothermal strategy with enhanced Li storage properties

Carbonate is recently studied as anode material for lithium ion battery due to its relatively high capacity compared to relative oxides. In order to improve the time-efficiency of synthesis, an ultrafast solvothermal process assisted with microwave is carried out to obtain well-constructed Mn0.8Co0.2CO3/graphene composite as anode material for lithium ion batteries. The as-prepared Mn0.8Co0.2CO3/graphene composite with a graphene amount of 17.5wt% exhibits a morphology of cubic particles in graphene without any impurity. Mn0.8Co0.2CO3/graphene delivers high initial charge capacities of 1033mAhg−1. And after 120 cycles, charge/discharge capacities of 737/735mAhg−1 are maintained at 0.2Ag−1. Even at 2Ag−1, the composite can still deliver high charge/discharge capacities of 500/501mAhg−1. It is promising to obtain carbonate/graphene anode materials rapidly through such ultrafast solvothermal process assisted by microwave for application.

Instantaneous Synthesis of Faceted Iron Oxide Nanostructures Using Microwave Solvothermal Assisted Combustion Technique

Microwaves are routinely used in the contemporary chemical synthesis of nanomaterials to increase the reaction kinetics and reduce the reaction time. In the present investigation, microwaves have been used in two step solvothermal and combustion method for the synthesis of iron oxide (α-Fe2O3) nanostructures. The structural examination reveals formation of hematite phase of iron oxide. Morphological analysis shows formation of sheet and rod-like morphologies depending on reaction conditions. Owing to such morphologies enabling relatively large surface to volume ratio, these nanostructures can find useful applications in supercapacitors, photocatalysis and sensors.

Evolution of Reduced Graphene Oxide-SnS2 Hybrid Nanoparticle Electrodes in Li-Ion Batteries.

Hybrid nanomaterials where active battery nanoparticles are synthesized directly onto conductive additives such as graphene hold the promise of improving the cyclability and energy density of conversion and alloying type Li-ion battery electrodes. Here we investigate the evolution of hybrid reduced graphene oxide–tin sulfide (rGO-SnS2) electrodes during battery cycling. These hybrid nanoparticles are synthesized by a one-step solvothermal microwave reaction which allows for simultaneous synthesis of the SnS2 nanocrystals and reduction of GO. Despite the hybrid architecture of these electrodes, electrochemical impedance spectroscopy shows that the impedance doubles in about 25 cycles and subsequently gradually increases, which may be caused by an irreversible surface passivation of rGO by sulfur enriched conversion products. This surface passivation is further confirmed by post-mortem Raman spectroscopy of the electrodes, which no longer detects rGO peaks after 100 cycles. Moreover, galvanostatic intermittent titration analysis during the 1st and 100th cycles shows a drop in Li-ion diffusion coefficient of over an order of magnitude. Despite reports of excellent cycling performance of hybrid nanomaterials, our work indicates that in certain electrode systems, it is still critical to further address passivation and charge transport issues between the active phase and the conductive additive in order to retain high energy density and cycling performance.

Facile synthesis and characterization of Ti(1−x)CuxO2 nanoparticles for high efficiency dye sensitized solar cell applications

In this study, we demonstrate the facile synthesis of Ti(1−x)CuxO2 (x = 0.0, 0.03, 0.06 and 0.09) nanoparticles through solvothermal microwave irradiation (SMI) technique and explored their photocatalytic applications. A combined analysis of XRD, FESEM and TEM studies indicate that doping of Cu2+ in TiO2 lattice do not affect the microstructure of the particles. The UV–Vis. absorption study indicates that the introduction of Cu element lead to decrease in optical bandgap of TiO2 from 3.450 eV to 3.155 eV (for x = 0.0 to 0.09). By using Ti(1−x)CuxO2 nanoparticles photoanodes were prepared on transparent conductive fluorine doped tin oxide substrates by doctor-blade technique. The dye-sensitized solar cells (DSSCs) were assembled and an analysis was made to evaluate the variations in open-circuit voltage depending on the concentration of Cu in Ti(1−x)CuxO2. The optimum efficiency of 6.51% was found at Ti0.94Cu0.06O2 based DSSCs, which gives an efficiency improved by 4% compared with that of the cells based on pure TiO2 (6.26%). This work demonstrates that Ti(1−x)CuxO2 is a most fascinating material and has great potential for application in photoenergy conversion devices.