Patrik Schmuki

Friedrich-Alexander-University Erlangen-Nürnberg | FAU · Department of Materials Science and Engineering

Noble metal single atoms (SAs) on semiconductors are increasingly explored as co-catalysts to enhance the efficiency of photocatalytic hydrogen production. In this study, we introduce a “spontaneous deposition” approach to anchor Pd SAs onto graphitic carbon nitride (g-C3N4) using a highly dilute tetraaminepalladium(ii) chloride precursor. Maximize...

Pt single atoms (SAs) on TiO2 have been identified as effective co‐catalysts in solar photocatalytic H2 production. In this study, Pt SAs is deposited on single crystal anatase nanosheets (NSs) with minor (101) and major (001) facets and expose them to various thermal treatments in air, Ar, and Ar‐H2 environments. It is found that through Ar‐H2 ann...

Due to the bio-inert nature of titanium (Ti) and subsequent accompanying chronic inflammatory response, an implant’s stability and function can be significantly affected, which is why various surface modifications have been employed, including the deposition of titanium oxide (TiO2) nanotubes (TNTs) onto the native surface through the anodic oxidat...

The study revealed that Pt single atoms on TiO 2 enhance AO7 photodegradation through ˙O 2 ⁻ production but have no impact on RhB degradation. The distinct behavior is due to different reaction pathways, with Pt nanoparticles exhibiting minimal effect.

The use of metal single atoms (SAs) as co‐catalysts on semiconductors has emerged as a promising technology to enhance their photocatalytic hydrogen production performance. In this study, we describe the deposition of very low amounts of Pt SAs (<0.1 at %) on exfoliated graphitic carbon nitride (C3N4) by a direct Pt−deposition approach from highly...

Single‐atom (SA) cocatalysts (SACs) have garnered significant attention in photocatalysis due to their unique electronic properties and high atom utilization efficiency. This review provides an overview of the concept and principles of SA cocatalyst in photocatalysis, emphasizing the intrinsic differences to SAs used in classic chemical catalysis....

The use of metal single atoms (SAs) as co‐catalysts on semiconductors has emerged as a promising technology to enhance their photocatalytic hydrogen production performance. In this study, we describe the deposition of very low amounts of Pt SAs (<0.1 at%) on exfoliated graphitic carbon nitride (C3N4) by a direct Pt‐deposition approach from highly d...

TiO2 nanotubes flow through membranes (TNTsM) were fabricated via anodization of Ti foil and explored as a biosensing platform for creatinine detection. The electrodes were prepared in different configurations including...

Due to the bio-inert nature of titanium (Ti) and subsequent accompanying chronic inflammatory response, the implant’s stability and function can be significantly affected, leading in time to a poor osseointegration process. To overcome this challenge and improve the overall performance of Ti implants, various surface modifications have been employe...

The application of photoelectrochemical cells to the partial oxidation of biomass represents a promising avenue as a sustainable process for obtaining valuable products. However, achieving both efficient conversion rates and high selectivity of desired products remains a great challenge. In this study, the photoelectrochemical oxidation of glycerol...

Anodic TiO2 nanotube arrays decorated with Ni, Cu, and NiCu alloy thin films were investigated for the first time for the photocatalytic degradation of paracetamol in water solution under UV irradiation. Metallic co-catalysts were deposited on TiO2 nanotubes using magnetron sputtering. The influence of the metal layer composition and thickness on t...

Recently, the use of Pt in the form of single atoms (SA) has attracted considerable attention to promote the cathodic hydrogen production reaction from water in electrochemical or photocatalytic settings. First, produce suitable electrodes by Pt SA deposition on Direct current (DC)‐sputter deposited titania (TiO2) layers on graphene—these electrode...

Herein, the growth of transparent TiO 2 nanotube (NT) layers is investigated by complete self‐organized anodization of a metallic Ti layer on fluorine‐doped tin oxide glass, deposited by electron beam evaporation. An initiation‐free open‐top tube morphology can be obtained for such transparent TiO 2 NTs using an optimized second anodization approac...

The process of converting solar energy into chemical energy through photoelectrochemical (PEC) water splitting holds significant promise for hydrogen and oxygen gas production. In the current study, we have demonstrated the feasibility of designing a high-performance heterojunction photoanode in a scalable manner. This photoanode sensitizes visible...

CuInS2/Cu2O/TiO2 nanotubes (TNTs) heterojunction based hybrid material is presented for selective detection of cholesterol and ibuprofen. Anodic TNTs are co-decorated with Cu2O and CuInS2 quantum dots (QDs) using modified chemical...

Correction for ‘α-Fe 2 O 3 /TiO 2 3D hierarchical nanostructures for enhanced photoelectrochemical water splitting’ by Hyungkyu Han et al. , Nanoscale , 2017, 9 , 134–142, https://doi.org/10.1039/C6NR06908H.

The employment of single atoms (SAs), especially Pt SAs, as co‐catalysts in photocatalytic H2 generation has gained significant attention due to their exceptional efficiency. However, a major challenge in their application is the light‐induced agglomeration of these SAs into less active nanosized particles under photocatalytic conditions. This stud...

When using single atoms (SAs) as a co‐catalyst in photocatalytic H2 generation, achieving a well‐dispersed, evenly distributed and adjustable SA surface density on a semiconductor surface is a challenging task. In the present work we use the planar adsorption of tetrakis‐(4‐carboxyphenyl)‐porphyrin (TCPP) and its platinum coordinated analogue, Pt‐T...

When using single atoms (SAs) as a co‐catalyst in photocatalytic H2 generation, achieving a well‐dispersed, evenly distributed and adjustable SA surface density on a semiconductor surface is a challenging task. In the present work we use the planar adsorption of tetrakis‐(4‐carboxyphenyl)‐porphyrin (TCPP) and its platinum coordinated analogue, Pt‐T...

In this report, a 2D MOF nanosheet derived Pd single‐atom catalyst, denoted as Pd‐MOF, was fabricated and examined for visible light photocatalytic hydrogen evolution reaction (HER). This Pd‐MOF can provide a remarkable photocatalytic activity (a H2 production rate of 21.3 mmol/gh in the visible range), which outperforms recently reported Pt‐MOFs (...

In this report, a 2D MOF nanosheet derived Pd single‐atom catalyst, denoted as Pd‐MOF, was fabricated and examined for visible light photocatalytic hydrogen evolution reaction (HER). This Pd‐MOF can provide a remarkable photocatalytic activity (a H2 production rate of 21.3 mmol/gh in the visible range), which outperforms recently reported Pt‐MOFs (...

This contribution describes the self-assembling and self-activating nature of a TiO 2 photocatalyst that generates hydrogen from water in the absence of sacrificial species or noble metal co-catalysts [1]. Such system forms when nanoparticles of reduced anatase TiO 2 are illuminated in an aqueous Ni ²⁺ solution [2,3]. UV illumination creates in-sit...

Titanium dioxide (TiO2) is the material of choice for photocatalytic and electrochemical applications owing to its outstanding physicochemical properties. However, its wide bandgap and relatively low conductivity limit its practical application. Modifying TiO2 with carbon species is a promising route to overcome these intrinsic complexities. In thi...

Single atoms (SAs) represent not only a new frontier in classic heterogeneous catalysis but are also increasingly investigated as co‐catalysts in photocatalytic reactions. In contrast to classic catalysis, many photocatalytic platforms require only a very low SA loading density to reach a saturated photocatalytic activity. As a result, an optimized...

Decoration of semiconductor photocatalysts with cocatalysts is generally done by a step-by-step assembly process. Here, we describe the self-assembling and self-activating nature of a photocatalytic system that forms under illumination of reduced anatase TiO2 nanoparticles in an aqueous Ni²⁺ solution. UV illumination creates in situ a Ni⁺/TiO2/Ti³⁺...

Aerophilic surfaces immersed underwater trap films of air known as plastrons. Plastrons have typically been considered impractical for underwater engineering applications due to their metastable performance. Here, we describe aerophilic titanium alloy (Ti) surfaces with extended plastron lifetimes that are conserved for months underwater. Long-term...

Considering the urgent need for green energy carriers, hydrogen became a promising substitute for fossil fuel production via sustainable approach. Therefore, developing efficient photocatalysts using solar energy is the main issue. Here, we report experimental and computational studies on This preprint research paper has not been peer reviewed. Ele...

In recent years, the use of single atoms (SAs) has become of a rapidly increasing significance in photocatalytic H2 generation; here SA noble metals (mainly Pt SAs) can act as highly effective co-catalysts. The classic strategy to decorate oxide semiconductor surfaces with maximally dispersed SAs relies on "strong electrostatic adsorption" (SEA) of...

In the present work, the spontaneous dewetting of thin Au layers on single crystalline anatase nanosheets into narrow‐disperse Au nanoparticles is investigated. Patterns of the Au particles can be formed on the main facets of anatase that provide a high co‐catalytic activity for photocatalytic generation of H2. Dewetting is distinctly influenced by...

Wetting of solid surfaces is crucial for biological and industrial processes but is also associated with several harmful phenomena such as biofouling and corrosion that limit the effectiveness of various technologies in aquatic environments. Despite extensive research, these challenges remain critical today. Recently, we have developed a facile UV-...

Efficient cathodes for the hydrogen evolution reaction (HER) in acidic water electrolysis rely on the use of expensive platinum group metals (PGMs). However, to achieve economically viable operation, both the content of PGMs must be reduced and their intrinsically strong H adsorption mitigated. Herein, we show that the surface effects of hydrogenat...

Studies on single‐atom catalysts (SACs) with individually isolated metal atoms anchored on specific supports have gained great interest in photocatalysis due to their enhanced catalytic activity and optimal atom utilization. By providing an optimized number of active sites and enhancing their intrinsic activity, SACs afford a distinctive platform f...

TiO2 used as a light‐absorbing semiconductor represents the classic benchmark for photocatalytic solar energy conversion and many other photocatalytic reactions. Various strategies are developed to improve the photoresponse of TiO2‐based materials, such as bandgap engineering or surface sensitization in combination with nanostructuring and geometry...

Atomically dispersed Pt single atoms (SAs) have been reported to be a highly effective co-catalyst on TiO2 for photocatalytic H2 generation. Many TiO2 supports have been explored for hosting Pt...

With recent advances in the field of single-atoms (SAs) used in photocatalysis, an unprecedented performance of atomically dispersed co-catalysts has been achieved. However, the stability and agglomeration of SA co-catalysts on the semiconductor surface may represent a critical issue in potential applications. Here we describe the photoinduced dest...

In the last few years, the progress made in the field of nanotechnology has allowed researchers to develop and synthesize nanosized materials with unique physicochemical characteristics, suitable for various biomedical applications. Amongst these nanomaterials, metal oxide nanoparticles (MONPs) have gained increasing interest due to their excellent...

In this work, NiCu co‐catalysts on TiO2 are studied for photocatalytic hydrogen evolution. NiCu co‐catalyst films are deposited at room temperature by argon plasma sputtering on high aspect‐ratio anodic TiO2 nanotubes. To tune the Ni : Cu atomic ratio, alloys of various compositions were used as sputtering targets. Such co‐catalyst films are found...

With a distinct electronic structure and unsaturated coordination centers, supported single-atoms (SAs) have shown great potential in heterogeneous catalysis due to their superior activity, stability, and selectivity. Over the last few years, the fascination of SA-use spread also over photocatalysis, i.e., a particular case of heterogeneous catalys...

Single crystal anatase TiO 2 nanosheets (TNS) were grown on a fluorine‐doped tin oxide (FTO) substrate and then modified via multiple TiCl 4 treatments to produce a hierarchical TiO 2 structure. This high surface area hierarchical structure was then decorated with CdS (as a visible light absorber) using SILAR treatments. The resulting photoanodes p...

In recent years, defect engineering of titania via reduction treatments has shown a high promise for enabling efficient and co-catalyst-free photocatalytic H2 generation from methanol/water solutions. However defect engineering alters several properties of TiO2 simultaneously. Here we use pristine (white) and hydrogenated (grey) anatase nanosheets...

In this article, we report a simple ex situ Sn-doping method on hematite nanoflakes (coded as MSnO2-H) that can protect the nanoflake (NF) morphology against the 800 °C high-temperature annealing process and activate the photoresponse of hematite until 800 nm wavelength excitation. MSnO2-H has been fabricated by dropping SnCl4 ethanol solution on h...

In the present work, it is shown that anodic TiO2 nanotubes (NTs) can be decorated with Pt, Pd, Rh, and Au single atoms (SAs) by a simple “dark deposition” approach. Such TiO2 NTs with surface trapped noble metal SAs provide a high activity for photocatalytic H2 generation from pure water, i.e., in absence of a sacrificial agent. However, noble met...

For more than 20 years, Pt/TiO2 represents the benchmark photocatalyst/co‐catalyst platform for photocatalytic hydrogen (H2) generation. Here, single atom (SA) Pt is decorated on different polymorphs of TiO2 (anatase, rutile, and the mixed phase of P25) using a simple immersion anchoring approach. On P25 and anatase, Pt SAs act as highly effective...

In this work, we examine the photoelectrochemical response of TiO 2 layers prepared by reactive DC sputter deposition on conductive glass (FTO). We show that adequate conditioning of the FTO by a very thin (few nm thick) Ti interlayer and optimizing the sputter parameters, compact TiO 2 anatase layers can be produced that reach incident photocurren...

Wetting of surfaces plays a vital role in many biological and industrial processes. There are several phenomena closely related to wetting such as biofouling and corrosion that cause the deterioration of materials, while the efforts to prevent the degradation of surface functionality have spread over several millennia. Antifouling coatings have bee...

In the present work, we report on a preparation strategy for hematite phase‐pure photoanodes consisting of Sn‐doped hematite nanoflakes/hematite thin film bilayer nanostructure (Sn‐HB). This approach is based on a two‐step annealing process of pure iron films deposited on FTO substrates by advanced magnetron sputtering. While the high density hemat...

Herein we report a one‐step, low cost, photocatalytic method for the synthesis of graphene oxide (GO) from commercial graphite using grey TiO2 as a photocatalyst. GO formation is achieved by UV‐illumination of a slurry of well‐dispersed grey TiO2 and commercial graphite. Light‐induced valence‐band holes from grey TiO2 then lead to an oxidation and...

With the introduction of a new interdisciplinary field, osteoimmunology, today, it is well acknowledged that biomaterial-induced inflammation is modulated by immune cells, primarily macrophages, and can be controlled by nanotopographical cues. Recent studies have investigated the effect of surface properties in modulating the immune reaction, and l...

In recent years, single-atom (SA) catalysts have become strongly investigated in electrocatalysis and increasingly also in photocatalysis. Here we demonstrate that single-crystalline anatase TiO2 nanoflake (NF) layers after a facile thermal air annealing process provide suitable anchoring sites for Pt SAs. Remarkably, such air annealed (001) facete...

Titanium dioxide (TiO2) and, in particular, its anatase polymorph, is widely studied for photocatalytic H2 production. In the present work, we examine the importance of reactive facets of anatase crystallites on the photocatalytic H2 evolution from aqueous methanol solutions. For this, we synthesized anatase TiO2 nanocrystals with a large amount of...

The use of single atoms (SAs) has become a highly investigated topic in heterogeneous catalysis, electrocatalysis, and most recently also in photocatalysis. In the field of photocatalysis, Pt SAs on TiO2 have been reported to be a highly efficient co‐catalyst in solar H2 production. In the present work we investigate the deposition of Pt SAs and na...

We present a photoanode concept for photoelectrochemical (PEC) water splitting based on metal nanoparticles (Au, Ag, Cu) deposited on a Ti mirror (NPoM) to photosensitize an intermediate TiO2 layer to induce the harvesting of light with sub-bandgap photon energies. The generation of hot electron-hole pairs in metallic nanostructures can occur eithe...

The insertion of cations such as H⁺ and Li⁺ to TiO2 photoelectrodes is a universally recognized method to enhance the electric conductivity of TiO2 electrodes. In the present work we report on the fabrication and use of Li⁺ inserted TiO2 nanotubes (NTs) as a photoanode scaffold in dye-sensitized solar cells (DSSCs). Li⁺ was successfully inserted in...

Herein we systematically investigate the influence of hydrogenation time and temperature on defects formation, structural changes, and co-catalyst free photocatalytic activity for epitaxially grown anatase thin films on strontium titanate single crystals. The photocatalytic activity trend of the anatase epi layers is similar to that of anatase powd...

In the present work the authors show that anodic TiO2 nanotubes (NT) show excellent harvesting properties for Pt single atoms (Pt SAs) from highly dilute Pt solutions. The tube walls of anodic nanotubes, after adequate annealing to anatase, provide ample of suitable trapping sites—that is, surface Ti³⁺‐Ov (Ov: oxygen vacancy) defects that are highl...