The Influence of Graphene Oxide-Fe3O4 Differently Conjugated with 10-Hydroxycampthotecin and a Rotating Magnetic Field on Adenocarcinoma Cells.

Nanoparticles (e.g., graphene oxide, graphene oxide-Fe3O4 nanocomposite or hexagonal boron nitride) loaded with anti-cancer drugs and targeted at cancerous cells allowed researchers to determine the most effective in vitro conditions for anticancer treatment. For this reason, the main propose of the present study was to determine the effect of graphene oxide (GO) with iron oxide (Fe3O4) nanoparticles (GO-Fe3O4) covalently (c-GO-Fe3O4-HCPT) and non-covalently (nc-GO-Fe3O4-HCPT) conjugated with hydroxycamptothecin (HCPT) in the presence of a rotating magnetic field (RMF) on relative cell viability using the MCF-7 breast cancer cell line. The obtained GO-Fe3O4 nanocomposites demonstrated the uniform coverage of the graphene flakes with the nanospheres, with the thickness of the flakes estimated as ca. 1.2 nm. The XRD pattern of GO-Fe3O4 indicates that the crystal structure of the magnetite remained stable during the functionalization with HCPT that was confirmed with FTIR spectra. After 24 h, approx. 49% and 34% of the anti-cancer drug was released from nc-GO-Fe3O4-HCPT and c-GO-Fe3O4-HCPT, respectively. The stronger bonds in the c-GO-Fe3O4-HCPT resulted in a slower release of a smaller drug amount from the nanocomposite. The combined impact of the novel nanocomposites and a rotating magnetic field on MCF-7 cells was revealed and the efficiency of this novel approach has been confirmed. However, MCF-7 cells were more significantly affected by nc-GO-Fe3O4-HCPT. In the present study, it was found that the concentration of nc-GO-Fe3O4-HCPT and a RMF has the highest statistically significant influence on MCF-7 cell viability. The obtained novel nanocomposites and rotating magnetic field were found to affect the MCF-7 cells in a dose-dependent manner. The presented results may have potential clinical applications, but still, more in-depth analyses need to be performed.

Sugars induced exfoliation of porous graphitic carbon nitride for efficient hydrogen evolution in photocatalytic water-splitting reaction.

Photocatalytic hydrogen evolution holds great promise for addressing critical energy and environmental challenges, making it an important area in scientific research. One of the most popular photocatalysts is graphitic carbon nitride (gCN), which has emerged as a noteworthy candidate for hydrogen generation through water splitting. However, ongoing research aims to enhance its properties for practical applications. Herein, we introduce a green approach for the fabrication of porous few-layered gCN with surface modifications (such as oxygen doping, carbon deposition, nitrogen defects) with promoted performance in the hydrogen evolution reaction. The fabrication process involves a one-step solvothermal treatment of bulk graphitic carbon nitride (bulk-gCN) in the presence of different sugars (glucose, sucrose, and fructose). Interestingly, the conducted time-dependent process revealed that porous gCN exfoliated in the presence of fructose at 180 °C for 6 h (fructose_6h) exhibits a remarkable 13-fold promotion of photocatalytic hydrogen evolution compared to bulk-gCN. The studied materials were extensively characterized by microscopic and spectroscopic techniques, allowing us to propose a reaction mechanism for hydrogen evolution during water-splitting over fructose_6h. Furthermore, the study highlights the potential of employing a facile and environmentally friendly fructose-assisted solvothermal process to improve the efficiency and stability of catalysts based on graphitic carbon nitride.

Functional Bi2O3/Gd2O3 Silica-Coated Structures for Improvement of Early Age and Radiation Shielding Performance of Cement Pastes.

This study presents a new approach towards the production of sol-gel silica-coated Bi2O3/Gd2O3 cement additives towards the improvement of early mechanical performance and radiation attenuation. Two types of silica coatings, which varied in synthesis method and morphology, were used to coat Bi2O3/Gd2O3 structures and evaluated as a cement filler in Portland cement pastes. Isothermal calorimetry studies and early strength evaluations confirmed that both proposed coating types can overcome retarded cement hydration process, attributed to Bi2O3 presence, resulting in improved one day compressive strength by 300% and 251% (depending on coating method) when compared to paste containing pristine Bi2O3 and Gd2O3 particles. Moreover, depending on the type of chosen coating type, various rheological performances of cement pastes can be achieved. Thanks to the proposed combination of materials, both gamma-rays and slow neutron attenuation in cement pastes can be simultaneously improved. The introduction of silica coating resulted in an increment of the gamma-ray and neutron shielding thanks to the increased probability of radiation interaction. Along with the positive early age effects of the synthesized structures, the 28 day mechanical performance of cement pastes was not suppressed, and was found to be comparable to that of the control specimen. As an outcome, silica-coated structures can be successfully used in radiation-shielding cement-based composites, e.g. with demanding early age performances.

Highly Porous Carbon Flakes Derived from Cellulose and Nickel Phosphide Heterostructure towards Efficient Electrocatalysis of Oxygen Evolution Reaction.

This study delves into the pressing challenges of climate change and the escalating carbon dioxide (CO2) emissions by exploring hydrogen technology as a sustainable alternative. In particular, there is focus on nickel phosphide-based electrocatalysts, known for their promising performance in hydrogen evolution reactions (HERs) and oxygen evolution reactions (OERs). Therefore, here we have designed a facile strategy to deliver highly porous carbon flakes derived from cellulose fibers via carbonization at 850 °C, yielding highly porous structures and outstanding specific surface area (SSAcel_carb_850_act = 3164 m2/g) after activation. As-fabricated carbon was utilized as a support for Ni12P5 with an optimized mass ratio. Electrochemical testing revealed that the composite of Ni12P5 and carbon flakes with a ratio of 100:1, respectively, exhibited the most favorable kinetics for the oxygen evolution reaction (OER). Importantly, the durability tests of this sample demonstrated the most stable behavior and lowest potential change under high current density among the studied samples, making it a promising candidate in practical applications. Moreover, the analysis of electrocatalysts after an OER does not show any changes, indicating that the sample does not undergo undesired intermediate reactions and that unwanted products are not released, explaining its stable behavior. This provides a straightforward approach for creating a cellulose-derived composite with enhanced electroactivity and durability.

MIL-53(Al) assisted in upcycling plastic bottle waste into nitrogen-doped hierarchical porous carbon for high-performance supercapacitors.

Disposable aluminum cans and plastic bottles are common wastes found in modern societies. This article shows that they can be upcycled into functional materials, such as metal-organic frameworks and hierarchical porous carbon nanomaterials for high-value applications. Through a solvothermal method, used poly(ethylene terephthalate) bottles and aluminum cans are converted into MIL-53(Al). Subsequently, the as-prepared MIL-53(Al) can be further carbonized into a nitrogen-doped (4.52 at%) hierarchical porous carbon framework. With an optical amount of urea present during the carbonization process, the carbon nanomaterial of a high specific surface area of 1324 m2 g-1 with well-defined porosity can be achieved. These features allow the nitrogen-doped hierarchical porous carbon to perform impressively as the working electrode of supercapacitors, delivering a high specific capacitance of 355 F g-1 at 0.5 A g-1 in a three-electrode cell and exhibiting a high energy density of 20.1 Wh kg-1 at a power density of 225 W kg-1, while simultaneously maintaining 88.2% capacitance retention over 10,000 cycles in two-electrode system. This work demonstrates the possibility of upcycling wastes to obtain carbon-based high-performance supercapacitors.

Oxygen evolution reaction on MoS2/C rods-robust and highly active electrocatalyst.

Recently, water oxidation or oxygen evolution reaction (OER) in electrocatalysis has attracted huge attention due to its prime role in water splitting, rechargeable metal-air batteries, and fuel cells. Here, we demonstrate a facile and scalable fabrication method of a rod-like structure composed of molybdenum disulfide and carbon (MoS2/C) from parent 2D MoS2. This novel composite, induced via the chemical vapor deposition (CVD) process, exhibits superior oxygen evolution performance (overpotential = 132 mV at 10 mA cm-2and Tafel slope = 55.6 mV dec-1) in an alkaline medium. Additionally, stability tests of the obtained structures at 10 mA cm-2during 10 h followed by 20 mA cm-2during 5 h and 50 mA cm-2during 2.5 h have been performed and clearly prove that MoS2/C can be successfully used as robust noble-metal-free electrocatalysts. The promoted activity of the rods is ascribed to the abundance of active surface (ECSA) of the catalyst induced due to the curvature effect during the reshaping of the composite from 2D precursor (MoS2) in the CVD process. Moreover, the presence of Fe species contributes to the observed excellent OER performance. FeOOH, Fe2O3, and Fe3O4are known to possess favorable electrocatalytic properties, including high catalytic activity and stability, which facilitate the electrocatalytic reaction. Additionally, Fe-based species like Fe7C3and FeMo2S5offer synergistic effects with MoS2, leading to improved catalytic activity and durability due to their unique electronic structure and surface properties. Additionally, turnover frequency (TOF) (58 1/s at the current density of 10 mA cm-2), as a direct indicator of intrinsic activity, indicates the efficiency of this catalyst in OER. Based onex situanalyzes (XPS, XRD, Raman) of the electrocatalyst the possible reaction mechanism is explored and discussed in great detail showing that MoS2, carbon, and iron oxide are the main active species of the reaction.

In vivo study on borophene nanoflakes interaction with Tenebrio molitor beetle: viability of hemocytes and short-term immunity effect.

The family of graphene-based materials welcomed a new member, borophene, in 2014. Research on synthesis routes and experimental study on physicochemical and biological (especially in vivo) properties still is strongly desired in order to evaluate its practical potential as a drug delivery-system. The effect of two-dimensional borophene nanoflakes on cells, systems and the entire animal organism has not been studied so far. Therefore, we investigated in vivo its biocompatibility with hemocytes in the Tenebrio molitor as a model organism. Short-term studies demonstrated that borophene nanoflakes at doses of 0.5, 1 or 2 µg of nanoflakes per insect did not induce hemocytotoxicity. Hemocytes exposed to nanoflakes showed morphology, adhesiveness and ability to form filopodia as in the control hemocytes. A detailed study indicates that borophene nanoflakes do not: (i) generate intracellular reactive oxygen species in hemocytes, (ii) affect the mitochondrial membrane potential and (iii) interfere with phagocytosis. Therefore, this contribution presents new in vivo insights into the group of two-dimensional materials which are one of the most promising materials for biomedical applications owing to their special structure and unique properties. However, long-term studies in insects and other animals are still necessary to confirm that borophene is biocompatible and biologically safe.

Ball milling induced borophene flakes fabrication.

To fill the knowledge gap for borophene, as the youngest member of the two-dimensional (2D) nanomaterials family, a facile, cost effective, scalable and reproducible fabrication route is still strongly required. Among so far studied techniques the potential of pure mechanical processes such as ball milling is not explored yet. Therefore, in this contribution, we explore the efficiency to exfoliate bulk boron into a few-layered borophene induced by mechanical energy in the planetary ball mill. It was revealed that the resulting flakes thickness and distribution can be controlled by (i) rotation speed (250-650 rpm), (ii) time of ball-milling (1-12 hours), and mass loading of bulk boron (1-3 g). Furthermore, the optimal conditions for the ball-milling process to induce efficient mechanical exfoliation of boron were determined to be 450 rpm, 6 hours, and 1 g (450 rpm_6 h_1 g), which resulted in the fabrication of regular and thin few-layered borophene flakes (∼5.5 nm). What is more, the mechanical energy induced during ball-milling, and the heat generated inside, affected the structure of borophene resulting in different crystalline phases. Besides being an additional and interesting discovery, it will also open up opportunities to investigate the relevance between the properties and the emerging phase. Structures labeled as ß-rhombohedral, γ-orthorhombic, τ-B and the conditions under which they appear, have been described. Therefore, in our study, we open a new door to obtain a bulk quantity of few-layered borophene for further fundamental studies and practical potential assessment.

Facile Strategy for Boosting of Inorganic Fillers Retention in Paper.

Achieving the desired properties of paper such as strength, durability, and printability remains challenging. Paper mills employ calcium carbonate (CaCO3) as a filler to boost paper's brightness, opacity, and printability. However, weak interaction between cellulose fibers and CaCO3 particles creates different issues in the papermaking industry. Therefore, this study explores the influence of various inorganic additives as crosslinkers such as mesoporous SiO2 nanospheres, TiO2 nanoparticles, h-BN nanoflakes, and hydroxylated h-BN nanoflakes (h-BN-OH) on inorganic fillers content in the paper. They were introduced to the paper pulp in the form of a polyethylene glycol (PEG) suspension to enable bonding between the inorganic particles and the paper pulp. Our findings have been revealed based on detailed microscopic and structural analyses, e.g., transmission and scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and N2 adsorption/desorption isotherms. Finally, the inorganic fillers (CaCO3 and respective inorganic additives) content was evaluated following ISO 1762:2001 guidelines. Conducted evaluations allowed us to identify the most efficient crosslinker (SiO2 nanoparticles) in terms of inorganic filler retention. Paper sheets modified with SiO2 enhance the retention of the fillers by ~12.1%. Therefore, we believe these findings offer valuable insights for enhancing the papermaking process toward boosting the quality of the resulting paper.

Bottom up approach of metal assisted electrochemical exfoliation of boron towards borophene.

Electrochemical exfoliation of nonconductive boron to few-layered borophene is reported. This unique effect is achieved via the incorporation of bulk boron into metal mesh inducing electrical conductivity and opening a venue for borophene fabrication via this feasible strategy. The experiments were conducted in various electrolytes providing a powerful tool to fabricate borophene flakes with a thickness of ~ 3-6 nm with different phases. The mechanism of electrochemical exfoliation of boron is also revealed and discussed. Therefore, the proposed methodology can serve as a new tool for bulk scale fabrication of few-layered borophene and speed up the development of borophene-related research and its potential application.

Waste-based nanoarchitectonics with face masks as valuable starting material for high-performance supercapacitors.

Surgical face masks waste is a source of microplastics (polymer fibres) and inorganic and organic compounds potentially hazardous for aquatic organisms during degradation in water. The monthly use of face masks in the world is about 129 billion for 7.8 billion people. Therefore, in this contribution the utilization of hazardous surgical face masks waste for fabrication of carbon-based electrode materials via KOH-activation and carbonization was investigated. The micro-mesoporous materials were obtained with specific surface areas in the range of 460 - 969 m2/g and a total pore volume of 0.311 - 0.635 cm3/g. The optimal sample showed superior electrochemical performance as an electrode material in supercapacitor in the three-electrode system, attaining 651.1F/g at 0.1 Ag-1 and outstanding capacitance retention of 98 % after a test cycle involving 50'000 cycles. It should be emphasized that capacitance retention is one of the most crucial requirements for materials used as the electrodes in the supercapacitor devices. In this strategy, potentially contaminated face masks, common pandemic waste, is recycled into highly valuable carbon material which can serve in practical applications overcoming the global energy crisis. What is more, all microorganisms, including coronaviruses that may be on/in the masks, are completely inactivated during KOH-activation and carbonization.

Nanoparticles Influence Lytic Phage T4-like Performance In Vitro.

Little is known about interactions of non-filamentous, complex-structured lytic phages and free, non-ordered nanoparticles. Emerging questions about their possible bio-sanitization co-applications or predictions of possible contact effects in the environment require testing. Therefore, we revealed the influence of various nanoparticles (NPs; SiO2, TiO2-SiO2, TiO2, Fe3O4, Fe3O4-SiO2 and SiO2-Fe3O4-TiO2) on a T4-like phage. In great detail, we investigated phage plaque-forming ability, phage lytic performance, phage progeny burst times and titers by the eclipse phase determinations. Additionally, it was proved that TEM micrographs and results of NP zeta potentials (ZP) were crucial to explain the obtained microbiological data. We propose that the mere presence of the nanoparticle charge is not sufficient for the phage to attach specifically to the NPs, consequently influencing the phage performance. The zeta potential values in the NPs are of the greatest influence. The threshold values were established at ZP < −35 (mV) for phage tail binding, and ZP > 35 (mV) for phage head binding. When NPs do not meet these requirements, phage−nanoparticle physical interaction becomes nonspecific. We also showed that NPs altered the phage lytic activity, regardless of the used NP concentration. Most of the tested nanoparticles positively influenced the phage lytic performance, except for SiO2 and Fe3O4-SiO2, with a ZP lower than −35 (mV), binding with the phage infective part­the tail.

Intumescent flame retardants inspired template-assistant synthesis of N/P dual-doped three-dimensional porous carbons for high-performance supercapacitors.

Heteroatom-doped three-dimensional (3D) porous carbons possess great potential as promising electrodes for high-performance supercapacitors. Inspired by the inherent features of intumescent flame retardants (IFRs) with universal availability, rich heteroatoms and easy thermal-carbonization to form porous carbons, herein we proposed a self-assembling and template self-activation strategy to produce N/P dual-doped 3D porous carbons by nano-CaCO3 template-assistant carbonization of IFRs. The IFRs-derived carbon exhibited large specific surface area, well-balanced hierarchical porosity, high N/P contents and interconnected 3D skeleton. Benefitting from these predominant characteristics on structure and composition, the assembled supercapacitive electrodes exhibited outstanding electrochemical performances. In three-electrode 6 M KOH system, it delivered high specific capacitances of 407 F g-1 at 0.5 A g-1, and good rate capability of 61.2% capacitance retention at 20 A g-1. In two-electrode organic EMIMBF4/PC system, its displayed high energy density of 62.8 Wh kg-1 at a power density of 748.4 W kg-1, meanwhile it had excellent cycling stability with 84.7% capacitance retention after 10,000 cycles. To our best knowledge, it is the first example to synthesize porous carbon from IFRs precursor. Thus, the current work paved a novel and low-cost way for the production of high-valued carbon material, and expanded its application for high-performance energy storage devices.

Sandwich-type architecture film based on WS2 and ultrafast self-expanded and reduced graphene oxide in a Li-ion battery.

Since its discovery, graphene has been widely considered a great material that has advanced the Li-ion battery field and allowed development in its performance. However, most current graphene-related research is focused on graphene-based composites as electrode materials, highlighting the role of graphene in composite materials. Herein, we focused on a three-dimensional composite film with unique sandwich-type architecture based on ultrafast self-expanded and reduced graphene oxide (userGO) and exfoliated WS2. This strategy allows non-active agents [e.g., carbon black and poly (vinylidene fluoride)] free electrodes in LIBs in the form of a film. The ultra-quick exothermal nature of the USER reaction allows the rapid release of internally generated gases to create highly porous channels inside the film. Hence, the improved Li-ion transport in the LIBs boosted the electrochemical performance of both film components (ex-WS2 and reduced graphene), resulting in a high specific capacity of 762 mAh/g at .05 A/g and high Coulombic efficiency (101%) after 1,000 cycles. Overall, userGO showed the highest capacity at a low current, and ex-WS2 provided a higher reversible capacity. These results showed that the expanded graphene layer is an excellent shield for ex-WS2 to protect against pulverization, promoting both stability and capacity.

Influence of Hydrogenation on Morphology, Chemical Structure and Photocatalytic Efficiency of Graphitic Carbon Nitride.

In this contribution, the effect of hydrogenation conditions atmosphere (temperature and time) on physicochemical properties and photocatalytic efficiency of graphitic carbon nitride (g-C3N4, gCN) was studied in great details. The changes in the morphology, chemical structure, optical and electrochemical properties were carefully investigated. Interestingly, the as-modified samples exhibited boosted photocatalytic degradation of Rhodamine B (RhB) with the assistance of visible light irradiation. Among modified gCN, the sample annealed at 500 °C for 4 h (500-4) in H2 atmosphere exhibited the highest photocatalytic activity-1.76 times higher compared to pristine gCN. Additionally, this sample presented high stability and durability after four cycles. It was noticed that treating gCN with hydrogen at elevated temperatures caused the creation of nitrogen vacancies on gCN surfaces acting as highly active sites enhancing the specific surface area and improving the mobility of photogenerated charge carriers leading to accelerating the photocatalytic activity. Therefore, it is believed that detailed optimization of thermal treatment in a hydrogen atmosphere is a facile approach to boost the photoactivity of gCN.

Co-Existence of Iron Oxide Nanoparticles and Manganese Oxide Nanorods as Decoration of Hollow Carbon Spheres for Boosting Electrochemical Performance of Li-Ion Battery.

Here, we report that mesoporous hollow carbon spheres (HCS) can be simultaneously functionalized: (i) endohedrally by iron oxide nanoparticle and (ii) egzohedrally by manganese oxide nanorods (FexOy/MnO2/HCS). Detailed analysis reveals a high degree of graphitization of HCS structures. The mesoporous nature of carbon is further confirmed by N2 sorption/desorption and transmission electron microscopy (TEM) studies. The fabricated molecular heterostructure was tested as the anode material of a lithium-ion battery (LIB). For both metal oxides under study, their mixture stored in HCS yielded a significant increase in electrochemical performance. Its electrochemical response was compared to the HCS decorated with a single component of the respective metal oxide applied as a LIB electrode. The discharge capacity of FexOy/MnO2/HCS is 1091 mAhg-1 at 5 Ag-1, and the corresponding coulombic efficiency (CE) is as high as 98%. Therefore, the addition of MnO2 in the form of nanorods allows for boosting the nanocomposite electrochemical performance with respect to the spherical nanoparticles due to better reversible capacity and cycling performance. Thus, the structure has great potential application in the LIB field.

Fabrication of Paper Sheets Coatings Based on Chitosan/Bacterial Nanocellulose/ZnO with Enhanced Antibacterial and Mechanical Properties.

Here, we designed paper sheets coated with chitosan, bacterial cellulose (nanofibers), and ZnO with boosted antibacterial and mechanical activity. We investigated the compositions, with ZnO exhibiting two different sizes/shapes: (1) rods and (2) irregular sphere-like particles. The proposed processing of bacterial cellulose resulted in the formation of nanofibers. Antimicrobial behavior was tested using E. coli ATCC® 25922™ following the ASTM E2149-13a standard. The mechanical properties of the paper sheets were measured by comparing tearing resistance, tensile strength, and bursting strength according to the ISO 5270 standard. The results showed an increased antibacterial response (assigned to the combination of chitosan and ZnO, independent of its shape and size) and boosted mechanical properties. Therefore, the proposed composition is an interesting multifunctional mixture for coatings in food packaging applications.

Boosting of photocatalytic hydrogen evolution via chlorine doping of polymeric carbon nitride.

Chlorine is found to be a suitable element for the modification of polymeric carbon nitride properties towards an efficient visible-light photocatalytic activity. In this study, chlorine-doped polymeric carbon nitride (Cl-PCN) has been examined as a photocatalyst in the hydrogen evolution reaction. The following aspects were found to enhance the photocatalytic efficiency of Cl-PCN: (i) unique location of Cl atoms at the interlayers of PCN instead of on its π-conjugated planes, (ii) slight bandgap narrowing, (iii) lower recombination rate of the electron-hole pairs, (iv) improved photogenerated charge transport and separation, and (v) higher reducing ability of the photogenerated electrons. The above factors affected the 4.4-fold enhancement of the photocatalytic efficiency in hydrogen evolution in comparison to the pristine catalyst.

0D, 1D, 2D molybdenum disulfide functionalized by 2D polymeric carbon nitride for photocatalytic water splitting.

Photocatalytic activity of molybdenum disulfide structures with different dimensions (0D, 1D and 2D) functionalized with polymeric carbon nitride (PCN) is presented. MoS2nanotubes (1D), nanoflakes (2D) and quantum dots (0D, QDs) were used, respectively, as co-catalysts of PCN in photocatalytic water splitting reaction to evolve hydrogen. Although, 2D-PCN showed the highest light absorption in visible range and the most enhanced photocurrent response after irradiation with light from 460 to 727 nm, QDs-PCN showed the highest photocatalytic efficiency. The detailed analysis revealed that the superior photocatalytic activity of QDs-PCN in comparison with other structures of MoS2arose from (i) the most effective separation of photoexcited electron-hole pairs, (ii) the most enhanced up-converted photoluminescence (UCPL), (iii) the highest reactivity of electrons in conduction band. Moreover, a narrowed size of QDs affected shorter diffusion path of charge carriers to active reaction sites, higher number of the sites and higher interfacial area between molybdenum disulfide and PCN.

The impact of environmental water on the potential application of core-shell titania-silica nanospheres as photocatalysts.

In this study, the core-shell silica nanospheres modified with titanium dioxide were tested in the photocatalytic decomposition of dyes. The presented data underlines the advantages and shortcomings in the potential application of silica-based catalysts to neutralize organic pollutants. During the photocatalytic reaction in distilled water, catalysts showed decreased efficiency due to a carbon layer deposited on its surface. This finding set an additional goal to investigate the possibility of regenerating the photocatalyst. Studies have shown that the catalyst could be successfully reused following the thermal removal of deposited carbon.Furthermore, the reactivated silica-titania catalysts exhibited comparable photocatalytic performance to the newly made nanomaterial. Surprisingly, catalyst application in the river water eventually resulted in the permanent deactivation of silica-titania nanospheres, which was caused by the interchangeable silica dissolution/precipitation process on the surface of the studied nanomaterial. In environmental water, silica dissolves and precipitates on titanium dioxide's surface, blocking the interaction between organic compounds and TiO2. The deactivation occurring in the environmental samples is irreversible. In distilled water, the decomposition of organic compounds leads to photocatalysts' deactivation by forming a carbon layer on their surface. Reactivation of the silica-based photocatalyst after distilled water is achievable by annealing at a high temperature. In light of our findings, the combination of the photocatalytic properties of TiO2and the silica template shows no prospects in the purification of polluted waste or environmental water.