High-performance Photocatalysts Research Articles

Linkage-Mediated Electronic Structure Modulation in Multicomponent Covalent Organic Frameworks for Dramatically Promoted Photocatalytic Hydrogen Evolution.

Linkage chemistry is an essential aspect to covalent organic framework (COF) applications; it is highly desirable to precisely modulate electronic structure mediated directly by linkage for efficient COF-based photocatalytic hydrogen evolution, which however, remains substantially challenging. Herein, as a proof of concept, a collection of robust multicomponent pyrene-based COFs with abundant donor-acceptor (D-A) interactions has been judiciously designed and synthesized through molecularly engineering linkage for photogeneration of hydrogen. Controlled locking and conversion of linkage critically contribute to continuously regulating COFs' electronic structures further to optimize photocatalytic activities. Remarkably, the well-modulated optoelectronic properties turn on the average hydrogen evolution rate from zero to 15.67mmol g-1h-1by the protonated quinoline-linked COF decorated with the trifluoromethyl group (TT-PQCOF-CF3). Using diversified spectroscopy and theoretical calculations, we show thatmultiple modifications toward linkagesynergistically lead to the redistribution of charge on COFs with extended π-conjugation and reinforced D-A effect, making TT-PQCOF-CF3a promising material with significantly boosted carrier separation and migration.This study provides important guidance for the design of high-performance COF photocatalysts based on the strategy of linkage-mediated electronic structure modulationin COFs.

Vertical Dipole Dominates Charge Carrier Lifetime in Monolayer Janus MoSSe.

Two-dimensional semiconductor materials with vertical dipoles are promising photocatalysts as vertical dipoles not only promote the electron-hole separation but also enhance the carrier redox ability. However, the influence of vertical dipoles on carrier recombination in such materials, especially the competing relationship between vertical dipoles and band gaps, is not yet clear. Herein, first-principles calculations and nonadiabatic molecular dynamics simulations were combined to clarify the influence of band gap and vertical dipole on the carrier lifetime in Janus MoSSe monolayer. By comparing with the results of MoS2 and MoSe2 as well as exploring the carrier lifetime of MoSSe under strain regulation, it has been demonstrated that the vertical dipole, rather than the band gap, is the dominant factor affecting the carrier lifetime. Strikingly, a linear relationship between the carrier lifetime and vertical dipole is revealed. These findings have important implications for the design of high-performance photocatalysts and optoelectronic devices.

Cu2O based NiCo2O4/GDY double S-scheme heterojunction for enhanced photocatalytic hydrogen production

Graphdiyne (GDY) is flourishing in the field of photocatalysis due to its high conductivity and enhancement of electron transfer. Electron transport can be expedited when GDY is used as a catalytic support. Herein, a GDY/NiCo2O4 composite photocatalyst was constructed in situ using organic compounds and bimetallic oxides. Furthermore, Cu2O was introduced into the GDY/NiCo2O4 interface through interfacial engineering, which effectively enhanced the activity of the catalyst. Electrochemistry and fluorescence spectroscopy demonstrated that the load of Cu2O can reduce the electron transfer resistance and decrease the photogenerated carrier recombination carrier rate. The formation of S-scheme heterojunction formed by Cu2O, GDY and NiCo2O4 can accelerate the electron transfer through band bending and internal electric field and improve the reducing activity of the catalyst. The outcomes of this work demonstrate the potential applications of Cu2O and GDY in photocatalysis and provide insights into the construction of high-performance photocatalysts.

Regulating the Topology of Covalent Organic Frameworks for Boosting Overall H2O2 Photogeneration.

Photocatalytic oxygen reduction reactions and water oxidation reactions are extremely promising green approaches for massive H2O2 production. Nonetheless, constructing effective photocatalysts for H2O2 generation is critical and still challenging. Since the network topology has significant impacts on the electronic properties of two dimensional (2D) polymers, herein, for the first time, we regulated the H2O2 photosynthetic activity of 2D covalent organic frameworks (COFs) by topology. Through designing the linking sites of the monomers, we synthesized a pair of novel COFs with similar chemical components on the backbones but distinct topologies. Without sacrificial agents, TBD-COF with cpt topology exhibited superior H2O2 photoproduction performance (6085 and 5448 μmol g-1 h-1 in O2 and air) than TBC-COF with hcb topology through the O2-O2⋅--H2O2, O2-O2⋅--O2 1-H2O2, and H2O-H2O2 three paths. Further experimental and theoretical investigations confirmed that during the H2O2 photosynthetic process, the charge carrier separation efficiency, O2⋅- generation and conversion, and the energy barrier of the rate determination steps in the three channels, related to the formation of *OOH, *O2 1, and *OH, can be well tuned by the topology of COFs. The current study enlightens the fabrication of high-performance photocatalysts for H2O2 production by topological structure modulation.

Engineering Built-In Electric Field Microenvironment of CQDs/g-C3N4 Heterojunction for Efficient Photocatalytic CO2 Reduction.

Graphitic carbon nitride (CN), as a nonmetallic photocatalyst, has gained considerable attention for its cost-effectiveness and environmentally friendly nature in catalyzing solar-driven CO2 conversion into valuable products. However, the photocatalytic efficiency of CO2 reduction with CN remains low, accompanied by challenges in achieving desirable product selectivity. To address these limitations, a two-step hydrothermal-calcination tandem synthesis strategy is presented, introducing carbon quantum dots (CQDs) into CN and forming ultra-thin CQD/CN nanosheets. The integration of CQDs induces a distinct work function with CN, creating a robust interface electric field after the combination. This electric field facilitates the accumulation of photoelectrons in the CQDs region, providing an abundant source of reduced electrons for the photocatalytic process. Remarkably, the CQD/CN nanosheets exhibit an average CO yield of 120µmol g-1, showcasing an outstanding CO selectivity of 92.8%. The discovery in the work not only presents an innovative pathway for the development of high-performance photocatalysts grounded in non-metallic CN materials employing CQDs but also opens new avenues for versatile application prospects in environmental protection and sustainable cleaning energy.

Fabrication of porous biochar supported Bi2MoO6 photocatalyst for efficient degradation of ciprofloxacin in seawater under visible light irradiation: Mechanistic investigation and intermediates analysis

Efficient separation of photocarriers is a critical approach for advancing high-performance photocatalyst systems to effectively remove environmental contaminants. In this investigation, a hydrothermal technique was employed to synthesize composites of Bi2MoO6 and porous biochar derived from banana peels (BPB). The samples underwent various characterization methods to assess their composition, morphology, and photoelectrochemical properties. The BPB/Bi2MoO6 composite exhibited a synergistic adsorption and photocatalytic impact in eliminating the antibiotic ciprofloxacin (CIP) from pure water and seawater. The optimized BPB/Bi2MoO6 sample displayed a significant degradation efficiency of 98.7 % for CIP after 90 min of visible-light exposure in pure water. In artificial seawater, the degradation efficiency for CIP remained high at 93.6 %, which was 12.2 times greater than that of pure Bi2MoO6. The study also explored the impact of various factors such as catalyst dosage, solution pH, and pollutant concentration on the photocatalytic performance of BPB/Bi2MoO6. Moreover, the catalyst exhibited enhanced efficiency in the adsorption-photocatalytic degradation of CIP within a continuous flow reaction system. The enhanced photocatalytic performance was attributed to the composite's exceptional adsorption capacity, enhanced response to visible light, and efficient separation of photoinduced electron-hole pairs. Furthermore, the BPB/Bi2MoO6 photocatalyst displayed good stability and recyclability over five consecutive photodegradation cycles. Radical trapping and electron spin resonance (ESR) experiments verified that the degradation of CIP was mainly driven by •OH and h+ radicals. A thorough investigation employing density functional theory (DFT), radical trapping and ESR tests, and liquid chromatography mass spectrometry (LC-MS) was conducted to elucidate the degradation mechanism and pathways. Furthermore, toxicity assessment software was utilized to illustrate the progressive reduction in toxicity of the intermediate products. In conclusion, this study provides valuable insights into the role of biochar in enhancing the photocatalytic degradation of pollutants and offers guidance for the future development of environmentally friendly photocatalysts.

High-Throughput Computational Screening of Novel Two-Dimensional Covalent Organic Frameworks for Efficient Photocatalytic Overall Water Splitting.

The pursuit of efficient photocatalysts toward photocatalytic water splitting has attracted wide attention. However, the low efficiency of photocatalytic reactions due to the rapid electron-hole recombination and the time-consuming searching process hinder the development of high-performance photocatalysts. Here, we proposed a data-driven screening procedure for covalent organic frameworks (COFs) as overall solar water-splitting photocatalysts. Based on a COF database through assembling different Cores and Linkers, three COFs are predicted to be efficient photocatalysts for overall solar water splitting after high-throughput computational screening. We found that the photogenerated electrons and holes are well separated on single COF photocatalysts without material engineering, and both hydrogen and oxygen evolution reactions can occur spontaneously on the three screened COFs under visible light radiation. This kind of novel COF screened by a data-driven screening procedure offers new perspectives for advancing efficient photocatalysts.

Efficient photocatalytic hydrogen production of Ni-Co layered double hydroxides (Ni-Co LDHs) anchored with reduced graphene oxide (rGO) hybrid composite

Using a suitable co-catalyst to boost photocatalytic H2 evolution from water splitting is crucial. Herein, we designed pristine NiCo-LDH and reduced graphene-oxide supported nickel-cobalt layered double hydroxide nanosheets (NiCo-LDH/rGO) as photocatalyst for the first time to evaluate the hydrogen production performance. Adding graphene has the potential to significantly increase electrical conductivity, and the supported NiCo-LDH has the potential to significantly reduce the likelihood of graphene self-aggregation. The effectiveness of its photocatalytic hydrogen generation was analyzed using a set of characterizations. The H2 evolution rates for pure rGO were 345.2 μmolh-1g-1, whereas those for Ni-Co LDH/rGO were 578.2 μmolh-1g-1. Average hydrogen generation per hour for the Ni-Co LDH/rGO composite material was 2032.1 μmolh-1g-1, which was 5.8 and 3.5 times that of rGO and Ni-Co LDH/rGO, respectively, NiCo-LDH@rGO's synergistic impact on the NiCo-LDH boosts the H2 generation pathway by increasing the catalyst's stability as well as performance by exposing active sites and speeding up electron transport. The produced nanocomposite shows excellent spatial charge separation and quicker electron transport across the conductive network of rGO, as shown by the photocurrent response test and photoluminescence (PL) spectra. The results of this study provide a fresh perspective on the practical use and synthesis of the inexpensive and effective NiCo-LDH/rGO, demonstrating the standard deviation of logical planning and preparation of high-performance photocatalysts.

Synergistic enhancement of photocatalytic efficiency and durability in CoNi-decorated Cu2O/Cu films for superior synthetic dye degradation

The Cu2O/Cu emerges as a promising candidate for photocatalytic application owing to its efficient photon absorption in the visible light spectrum. However, the susceptibility of Cu2O-based photocatalysts to self-decomposition diminishes their effectiveness. This study introduces CoNi as co-catalyst to enhance the durability of Cu2O/Cu photocatalyst. Electrodeposition was employed to decorate the Cu2O/Cu crystal surface with Co, Ni and CoNi. The deposition potential of CoNi was optimized to produce a high-performance photocatalyst. The utilization of CoNi co-catalyst resulted in significant enhancements in photoelectrochemical properties under light irradiation when compared to using a single Co or Ni co-catalyst, suggesting a synergistic effect between Co and Ni within the system. The enhancement is evidenced by a noteworthy increase in the photocurrent of the photocatalyst, rising from 10.24 mA/cm2 to 20.81 mA/cm2. In addition, the decoration of CoNi resulted in a reduction of the charge transfer resistance from 4.2 kΩ to 0.7 kΩ, while simultaneously increasing the electrochemically active surface area of the photocatalyst from 15.49 cm2 to 157.69 cm2. The observed modifications lead to a substantial improvement in the photocatalytic efficiency, resulting in an impressive 88 % degradation of methylene blue, which is 3.4 times higher than achieved in the absence of the co-catalyst. Moreover, there was a significant improvement in the photostability of the photocatalyst, with an increase from 16.81 % to 50.55 %. These findings demonstrate the significance of CoNi co-catalyst decoration in producing a highly active and durable photocatalyst, making it a promising candidate for efficient synthetic dyes degradation.

Surface vacancy engineering powered reverse cation exchange in preparing CuZnS hollow nanoboxs for efficient photocatalytic hydrogen evolution

The cation exchange technology plays a significant role in designing high-performance photocatalysts at atomic scale. However, the chemical kinetic energy barrier greatly limits the application of cation exchange strategies. Herein, an effective surface vacancy engineering powered reverse cation exchange strategy was exploited to realize energy-unfavored cation exchange reactions. Cu vacancies are created on the surface of Cu2-xS nanoboxs (Cu2-xS NBs), which are subsequently occupied by Zn2+ ions. A hollow CuZnS nanoboxs (CuZnS NBs) were successfully prepared for photocatalytic hydrogen evolution. The prepared CuZnS NBs has abundant interfacial Zn-S bonds, which promote interfacial charge transfer (IFCT) as a rapidly electron bridge. In particular, the photocatalytic hydrogen evolution rate of CuZnS NBs under visible light is 2.06 mmol·g−1·h−1, which is 5.9 times higher than that of Cu2-xS. The synthetic mechanism and photocatalytic mechanism of the CuZnS was investigated from experiment and theoretical calculations. The surface vacancy powered reverse cation exchange strategy offers a new opportunity for the rational tailoring new-generation photocatalysts at the atomic scale.

Regulation of Lewis acid sites on ZnO/SiW11Co for tunable photocatalytic activity toward water remediation

The function of surface acidity in catalytic reactions has been well studied in the field of conventional catalysis, nevertheless, regulating surface acidic sites and unveiling its roles during heterogeneous photocatalysis has been less frequently reported. To address this issue, we constructed a novel heterojunction photocatalyst of ZnO/SiW11Co with abundant Lewis acid sites for wastewater treatment. Under visible light irradiation, the optimal ZnO/SiW11Co was found to have the highest photocatalytic activity, achieving a degradation efficiency of 97.7% for Rhodamine B (RhB), 96.1% for tetracycline (TC), and 91.4% for methyl orange (MO). The RhB removal rate remained at 91.3% even after five cycles, indicating excellent stability and practicality of ZnO/SiW11Co. By compositing with SiW11Co, a typical polyoxometalates with unique super acid properties, ZnO/SiW11Co formed plentiful surface Lewis acid sites, as confirmed by the pyridine adsorption FT-IR and NH3-TPD. The as-formed Lewis acid sites could provide more active sites, making it easier for reactants to coordinate to the photocatalyst surface, which reduced the activation energy of photocatalytic reactions and accelerate RhB removal. Density functional theory (DFT) calculations unveiled the redistribution of electron-hole pairs, optimizing the light absorption and charge separation efficiency, which obeyed a Z-scheme mechanism. Combined active species capture experiments and electron spin resonance, •O2−, h+, and •OH were the main active substances for the photocatalytic degradation of RhB. Besides, the possible degradation pathways for RhB were analyzed using liquid chromatography-mass spectrometry (LC-MS). The work provided useful strategy for the design of high-performance photocatalysts via regulating surface Lewis acid sites toward water remediation.

A readily synthesized ZnIn2S4/attapulgite as a high-performance photocatalyst for Cr(VI) reduction

Herein, a ZnIn2S4-decorated attapulgite photocatalyst (ZnIn2S4/ATP) was successfully synthesized by a facile oil bath heating method. It shows superior reduction efficiency for the removal of Cr(Ⅵ). The improved photocatalytic performance is primarily attributed to the intercalation effect of ZnIn2S4 and attapulgite (ATP), enhanced separation efficiency of photogenerated electron-hole pairs, and improved transport efficiency of photogenerated carriers. Moreover, insight into the photocatalytic mechanism demonstrates that •O2− and e− are the major active species in the photocatalytic reduction of Cr(VI) over ZnIn2S4/ATP. This work serves as a reference for integrating natural clay with semiconductors for photocatalytic wastewater treatment.

Enhanced charge transfer via NH2-MIL-125@ NH2/H-MIL-125 hetero-frameworks for photocatalytic H2 evolution

The efficient transfer of photogenerated carriers is essential to the photocatalytic H2 evolution. Herein, we designed and synthesized a kind of novel NH2-MIL-125@NH2/H-MIL-125 hetero-frameworks with nanopore structure to drive efficient charge transfer for photocatalytic H2 evolution. Single-ligand NH2-MIL-125 (NM) and dual-ligand NH2/H-MIL-125 (NHM), which have similar composition, structure and well-matched energy band, were selected as the core and shell to prepare the NM@NHM hetero-framework as a proof-of-principle system. The hetero-framework strategy is proposed to intensify the charge transfer and thus enhance the photocatalytic activity. The H2 evolution rate of optimal NM@NHM hetero-framework can reach 2.25 mmol g−1 h−1 under visible light, much higher than pristine NM (0.726 mmol g−1 h−1) and NHM (1.27 mmol g−1 h−1). Such high performance can be attributed to the hetero-framework structure consisting of NM and NHM with similar composition and structure, which reduces the interfacial resistance in the charge transfer, thus facilitating the photocatalytic H2 evolution. Our work may provide a new strategy for the rational design of high-performance photocatalysts.

Regulating local charge distribution of single Ni sites in covalent organic frameworks for enhanced photocatalytic CO2 reduction

Covalent organic frameworks (COFs) engineered by single-atom sites have attracted significant attention for CO2 photoreduction. However, precisely manipulating the chemical environment of active sites on the COFs is a grand challenge. Herein, we synthesized a series of isostructural COFs for photocatalytic CO2 reduction, where the strong coordination conformation guides atomically dispersed metal sites to chelate spontaneously in the predesigned imine-pyridine position of COFs. Experimental and theoretical results revealed the crucial influence of the single-Ni site engineering and electronic structures of COF configuration on improving extended π-conjugation, exciton dissociation, charge separation efficiency, and charge carrier migration. Benefiting from the synergistic effect, the optimal Ni-TAPT-COF exhibited a record-high CO production rate of 25.5 mmol g-1h-1 and a selectivity of 98.8%, even natural-sunlight-driven diluted CO2 (10%). This work paves the way for the rational design of high-performance COF-based photocatalysts at the molecular level, highlighting their practical potential for CO2 photoreduction.

Significantly enhanced photocatalytic performance of the W-Zr-MOF-NH2@TpTt-COF heterostructure for tetracycline removal by defects engineering

A hollow heterojunction of W-Zr-MOF-NH2@TpTt-COF (WZT) was fabricated by combining etched W-Zr-MOF-NH2 with TpTt-COF. WZT, synthesized through acid etching and hydrothermal methods, showed better tetracycline degradation than pure W-Zr-MOF-NH2 and pure TpTt-COF due to its larger specific surface area and more active sites. The surface of WZT contains abundant oxygen vacancies (OVs) that capture electrons, promoting the separation of photogenerated e--h+ pairs and increasing WZT’s photocatalytic activity. WZT (1:1, mass) showed 87% degradation of tetracycline under 300 W Xenon lamp irradiation. The results of cycling experiments demonstrated the high stability and reusability of WZT (1:1), making it feasible for production. The excellent photocatalytic degradation of tetracycline by WZT (1:1) originates from the formation of heterojunctions and the presence of surface OVs, which reduces the strong photogenerated e--h+ complexation efficiency. Possible photocatalytic degradation mechanisms are proposed while demonstrating the formation of Z-scheme heterojunction in WZT, which aligned with the experimental results of electron spin resonance (ESR). The tetracycline oxidative decomposition process involves the participation of •OH, 1O2, •O2-, e-, and h+ as proven by ESR and radical trapping experiments. This work proposes a research idea to prepare high-performance photocatalysts with MOF@COF type, featuring OVs-rich and Z-scheme heterojunctions.

Emergence of enhanced photocatalytic response in GO-hBN nanocomposites with tuned non-linear optical and surface electronic properties

The hexagonal Boron Nitride (hBN) nanostructures with tuned physicochemical properties find huge applications in optoelectronic devices. Herein, we have synthesized nanocomposite of hBN with graphene oxide (GO) in various ratios to acquire composition-dependent variation in their structural, surface electronic, linear, and non-linear optical properties. The insertion of GO in hBN nanosheets has modified their strain landscape, the electronic charge transfers from GO to hBN, increased the working time of free charge carriers, and suppressed electron-hole recombination, thus modifying its work function (WF). GO-hBN nanocomposites observed to have reduced bandgap where creation of defect induced mid-gap states lead to enhancement in non-linear absorption of two photons. Herein, we have established a linear relationship between Urbach energy (Eu), a measure of disorders and non-linear absorption coefficient (αNL). Additionally, we have observed that the tuned bandgap of the nanocomposites has significantly enhanced their performance as high-performance photocatalysts for the degradation of methyl orange, compared to bare hBN or GO. As a result, we discovered that Eu, αNL, WF and photodegradation activity of GO-hBN nanocomposites exhibit analogous variations in response to changes in the content of GO. Thus, by strategically prioritizing the modification of a single parameter while considering the potential effects on other relevant properties for application purpose, GO-hBN can effectively harness large spectrum areas for catalytic and optoelectronic applications.

Internal electric field and oxygen vacancies synergistically boost S-scheme VO/BiOCl-TiO2 heterojunction film for photocatalytic degradation of norfloxacin

Sluggish interfacial dynamics and weak redox properties make the degradation of antibiotics by photocatalysts still a great challenge. Herein, constructing S-scheme heterojunction between BiOCl and TiO2 nanorod arrays (TNA) by hydrothermal method, and the synergistic effect of oxygen vacancies (VO) and Internal Electric Field (IEF) on improving the performance of the photocatalysts was revealed by adjusting the VO. The VO modified BiOCl-TiO2 (VBiTNA) exhibited excellent photocatalytic activities for norfloxacin, achieving a degradation efficiency of up to 90.2 % in just 60 min, and the rate constant was as high as 3.67 × 10-2 min−1. In addition, it also showed great photocatalytic degradation performance of NOR in a wide pH range, complex ionized water environment and real water source. The degradation intermediates and degradation pathway of NOR were predicted with LC-MS technology and Fukui function. Combined with free radical capture, electron paramagnetic resonance, relevant electrochemical testing, and DFT calculations reveals the mechanism of the enhanced photocatalytic performance of VBiTNA. The performance enhancement can be attributed to the expansion of the light absorption range, enhanced adsorption of O2 and effective activation to generate ·O2–, while improving the separation efficiency of electron-hole pairs and maintaining a strong redox capacity. This research focusing on VO and IEF mechanisms will help to advance the rational design of high-performance defective photocatalysts.

High-performance heterometallic photocatalysts afforded by polyoxometalate synthons for efficient H2 production

MoS2-based materials have emerged as photoelectric semiconductors characterized by a narrow band gap, high capacity for absorbing visible light, and reduced H2 adsorption energy comparable to Pt. These attributes render them appealing for application in photocatalytic hydrogen production. Despite these advantages, the widespread adoption of MoS2-based materials remains hindered by challenges associated with limited exposure to active sites and suboptimal catalytic hydrogen production efficiency. To address these issues, we have designed and synthesized a new class of highly dispersed bimetallic/trimetallic sulfide materials. This was achieved by developing polyoxometalate synthons containing Ni-Mo elements, which were subsequently reacted with thiourea and CdS. The resulting Ni3S2-MoS2 and Ni3S2-MoS2-CdS materials achieve photocatalytic hydrogen production rates of 2770 and 2873 μmol g–1h−1, respectively. Notably, the rate of 2873 μmol g–1h−1 for Ni3S2-MoS2-CdS surpassed triple (3.23 times) the performance of CdS and nearly sextuple (5.77 times) that of single MoS2. These materials outperformed the majority of MoS2-based photocatalysts. Overall, this study introduces a straightforward methodology for synthesizing bimetallic/trimetallic sulfides with enhanced photocatalytic H2 evolution performance. Our findings underscore the potential of transition metal sulfide semiconductors in the realm of photocatalysis and pave the way for the development of more sustainable energy production systems.

H-Glass Supported Hybrid Gold Nano-Islands for Visible-Light-Driven Hydrogen Evolution.

Flat panel reactors, coated with photocatalytic materials, offer a sustainable approach for the commercial production of hydrogen (H2) with zero carbon footprint. Despite this, achieving high solar-to-hydrogen (STH) conversion efficiency with these reactors is still a significant challenge due to the low utilization efficiency of solar light and rapid charge recombination. Herein, hybrid gold nano-islands (HGNIs) are developed on transparent glass support to improve the STH efficiency. Plasmonic HGNIs are grown on an in-house developed active glass sheet composed of sodium aluminum phosphosilicate oxide glass (H-glass) using the thermal dewetting method at 550°C under an ambient atmosphere. HGNIs with various oxidation states (Au0, Au+, and Au-) and multiple interfaces are obtained due to the diffusion of the elements from the glass structure, which also facilitates the lifetime of the hot electron to be ≈2.94ps. H-glass-supported HGNIs demonstrate significant STH conversion efficiency of 0.6%, without any sacrificial agents, via water dissociation. This study unveils the specific role of H-glass-supported HGNIs in facilitating light-driven chemical conversions, offering new avenues for the development of high-performance photocatalysts in various chemical conversion reactions for large-scale commercial applications.

Photodegradation of Phenol under Visible Light Irradiation Using Cu-N-codoped ZrTiO<sub>4</sub> Composite as a High-Performance Photocatalyst

Codoping of nitrogen and copper into zirconium titanate composite (Cu-N-codoped ZrTiO4) was carried out through a sol-gel process. This study aimed to investigate the effect of copper and nitrogen dopants on the photocatalytic activity of ZrTiO4 composite in degrading phenol. To prepare the composite, an aqueous suspension of zirconia (ZrO2) alongside a fixed amount of urea and various amount of copper sulfate was added dropwise into diluted titanium(IV) tetraisopropoxide (TTIP) in ethanol. The composites were calcined at temperatures of 500, 700, and 900 °C. Fourier-transform infrared spectrophotometry (FTIR), X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray (SEM-EDX) mapping, and specular reflectance UV-visible spectrophotometry (SR UV-vis) were used for their characterization of composite. The photocatalytic activity was evaluated by adding the composite into a 10 mg L−1 phenol solution for various irradiation time spans. The remaining concentration of phenol solution was determined by absorption at 269 nm. Cu-N-codoped ZrTiO4 composite containing 5% Cu calcined at 500 °C demonstrated the highest observed rate constant and a significant band gap decrease from 3.13 to 2.68 eV.