Photocatalytic Hydrogen Evolution Reaction Activity Research Articles

Synergistic vacancy defects and the surface hydrophobic-to-superhydrophilic wetting engineering in W/S co-doped BiOI for enhanced photocatalytic hydrogen evolution

Bismuth oxyhalide (BiOI) has been used for photoelectrochemical catalysis in the field of catalytic hydrogen evolution, but it in a single-phase form has hardly been reported for photocatalytic hydrogen evolution reaction (PHER). Herein, we designed a W/S co-doped BiOI-based superhydrophilic catalyst with oxygen vacancy-rich defects and heterovalent valence states for efficient PHER under visible light. The W/S doping in BiOI not only adjusts the energy band structure and expands the visible light response range, but also transforms its hydrophobicity into superhydrophilicity, with which the gas bubble amount can be reduced and PHER activity enhanced. The introduction of sulfur regulates the content of oxygen vacancies which enhance the active surface sites for capturing water molecules and activating the H-O-H bond. The added tungsten exists in different valence states of W6+ and W5+ which is beneficial for electron hopping and PHER activity. The W/S-BiOI-3 with the suitable W/S doping content exhibits the highest visible-light PHER rate of 9.46 mmol·g−1·h−1, with an apparent quantum efficiency (AQE) of 9.7 % at 420 nm. W/S-BiOI-3 shows excellent PHER activity, stability, and durability, which provides a feasible scheme for other bismuth-based halogen oxides to be used in PHER.

Water-Stable High-Entropy Metal-Organic Framework Nanosheets for Photocatalytic Hydrogen Production.

Metal-organic frameworks (MOFs) have emerged as promising platforms for photocatalytic hydrogen evolution reaction (HER) due to their fascinating physiochemical properties. Rationally engineering the compositions and structures of MOFs can provide abundant opportunities for their optimization. In recent years, high-entropy materials (HEMs) have demonstrated great potential in the energy and environment fields. However, there is still no report on the development of high-entropy MOFs (HE-MOFs) for photocatalytic HER in aqueous solution. Herein, the authors report the synthesis of a novel p-type HE-MOFssingle crystal (HE-MOF-SC) and the corresponding HE-MOFsnanosheets (HE-MOF-NS) capable of realizing visible-light-driven photocatalytic HER. Both HE-MOF-SC and HE-MOF-NS exhibit higher photocatalytic HER activity than all the single-metal MOFs, which are supposed to be ascribed to the interplay between the different metal nodes in the HE-MOFsthat enables more efficient charge transfer. Moreover, impressively, the HE-MOF-NS demonstrates much higher photocatalytic activity than the HE-MOF-SC due to its thin thickness and enhanced surface area. At optimum conditions, the rate of H2 evolution on the HE-MOF-NS is ≈13.24 mmol h-1 g-1, which is among the highest values reported for water-stable MOF photocatalysts. This work highlights the importance of developing advanced high-entropy materials toward enhanced photocatalysis.

2D/2D Molybdenum Sulfo Selenides/Black Phosphorus Heterostructures for Supercapacitors and Light‐Driven Hydrogen Generation Applications

Abstract2D transition metal dichalcogenide alloys are considered as the promising duo for energy storage and catalyst for light‐driven energy conversion applications due to their novel physicochemical properties. However, heterostructuring with other 2D materials is an effective strategy to enhance the charge storage kinetics as well as comprehensive spectral light response and efficient charge separation. Herein, Molybdenum sulfo selenide (MoSSe)/black phosphorous (BP) heterostructure is synthesized by a one‐pot solvothermal technique, and energy storage and conversion efficiency are characterized. Interestingly, the fabricated symmetric supercapacitor based on the MoSSe/BP hybrid shows an exceptional capacitance of 230 mF cm−2 with an excellent energy density of 31.9 µWh cm−2 and a power density of 805.7 µW cm−2. To validate the experimental findings, Density Functional Theory (DFT) computational simulations are carried out concurrently. The lower diffusion energy barrier for electrolytic ions, in the case of hybrid MoSSe/BP compared to pristine MoSSe, supports the higher charge storage performance. Finally, MoSSe/BP nanocomposites' photocatalytic hydrogen evolution reaction (HER) performance is evaluated under 400 W of UV–vis light, with eosin Y dye acting as a sensitizer and triethanolamine acting as a sacrificial agent. The MoSSe/BP nanocomposite exhibits the maximum photocatalytic HER activity of 5718 µmol h−1 g−1, greater than the bare MoSSe nanostructure.

Heterostructure with tightly-bound interface between In2O3 hollow fiber and ZnIn2S4 nanosheet toward efficient visible light driven hydrogen evolution

Visible-light-driven photocatalytic hydrogen evolution is considered as one of the most useful approaches to produce renewable fuels from abundant resources. Indium oxide (In2O3) has attracted much attention in the field of solar hydrogen production due to its moderate band gap, which can be driven by visible light easily. However, the efficiency of hydrogen evolution reaction (HER) of In2O3 is currently unsatisfactory. To enhance the HER efficiency of In2O3, herein, sandwich-structured In2O3/ZnIn2S4 heterostructure was precisely constructed via in-situ growth of ZnIn2S4 nanosheets on the In2O3 hollow fibers. The fabricated In2O3/ZnIn2S4 heterostructure exhibited a significantly enhanced photocatalytic HER activity of 2.18 mmol/g/h as compared to pure In2O3 and ZnIn2S4. Such efficient photocatalytic hydrogen production is attributed to the tightly-bound interface between (001) planes of flake ZnIn2S4 and (222) planes of In2O3. Experimental and theoretical investigation indicates compactly interface enabling efficient charge transfer and separation, which benefited the excellent photocatalytic HER performance.

Layered Nanocomposites of Polymer-Functionalized Reduced Graphene Oxide and Borocarbonitride with MoS2 and MoSe2 and Their Hydrogen Evolution Reaction Activity

Two dimensional heterostructure have been widely investigated for various applications in electrochemistry such as water splitting and battery storage. These heterostructures are mainly formed due to vander waals interaction, covalent cross-linking and electrostatic interactions. Herein, we have prepared nanocomposite of positively charged poly (diallyldimethylammonium chloride) (PDDA, shown as P)-functionalized reduced graphene oxide (RGO) and borocarbonitride (BC6N, shown as BCN for simplicity) sheets with layers of negatively charged MoS2 and MoSe2 by electrostatic interaction in solution phase. The nanocomposites exhibit superior photocatalytic hydrogen evolution reaction (HER) activity compared to the individual components, and the value increases with the MoS2/MoSe2 content. The highest photocatalytic HER activity obtained is 11230 μmol h–1 g–1 in the nanocomposite P.RGO-MoS2, with a P.RGO-MoS2 ratio of 1:5. The P.RGO-MoSe2 (1:5) and P.BCN-MoS2 (1:5) nanocomposites exhibit somewhat lower activities of 9540 and 8593 μmol h–1 g–1, respectively. Prompted by literature reports that carbon-rich BCNs are efficient HER electrocatalysts, we have examined the electrocatalytic HER activity of P.BCN-MoS2 (1:1, 1:5, and 1:7) nanocomposites. The electrocatalytic HER activity of P.BCN-MoS2 (1:5) is found to be extraordinary, with an onset potential of −50 mV (vs RHE), comparable to that of platinum.

Single-Site Ni-Grafted TiO2 with Diverse Coordination Environments for Visible-Light Hydrogen Production.

Solar hydrogen production at a high efficiency holds the significant importance in the age of energy crisis, while the micro-environment manipulation of active sites on photocatalysts plays a profound role in enhancing the catalytic performance. In this work, a series of well-defined single-site Ni-grafted TiO2 photocatalysts with unique and specific coordination environments, 2,2'-bipyridine-Ni-O-TiO2 (T-Ni Bpy) and 2-Phenylpyridine-Ni-O-TiO2 (T-Ni Phpy), were constructed with the methods of surface organometallic chemistry combined with surface ligand exchange for visible-light-induced photocatalytic hydrogen evolution reaction (HER). A prominent rate of 33.82 μmol ⋅ g-1 ⋅ h-1 and a turnover frequency of 0.451 h-1 for Ni are achieved over the optimal catalyst T-Ni Bpy for HER, 260-fold higher than those of Ni-O-TiO2 . Fewer electrons trapped oxygen vacancies and a larger portion of long-lived photogenerated electrons (>3 ns, ~52.9 %), which were demonstrated by the electron paramagnetic resonance and femtosecond transient IR absorption, correspond to the photocatalytic HER activity over the T-Ni Bpy. The number of long-lived free electrons injected from the Ni photoabsorber to the conduction band of TiO2 is one of the determining factors for achieving the excellent HER activity.

The effect of Ni and Co co-catalysts on the catalytic activity of mesoporous graphitic carbon nitride/black phosphorus/molybdenum disulfide heterojunctions in solar-driven hydrogen evolution

In this work, a ternary heterojunction photocatalyst composed of mesoporous graphitic carbon nitride, black phosphorus, and molybdenum disulfide (m-CN/BP/MoS2) was firstly fabricated for the visible-light-driven hydrogen evolution reaction (HER) via water splitting. The photocatalytic activity of m-CN/BP/MoS2 photocatalyst was further improved by incorporating Ni and Co co-catalysts, denoted as m-CN/BP/MoS2-Y (Y: Ni, Co). The final quaternary nanocomposites were experimentally demonstrated in the form of mixed heterojunctions (type-I, type-II, and Schottky junctions) to manipulate the photogenerated carriers with the aim of reducing their recombination rate and increasing the light-harvesting ability of the pristine components. To find the best combination of different semiconductors in the heterojunction to ensure the highest photocatalytic HER activity, the loading ratio of each component was optimized one-by-one by considering the rate of HER under the same conditions. The photocatalytic HER activity of m-CN/BP/MoS2-Ni (5 wt%) and m-CN/BP/MoS2-Co (0.5 wt%) photocatalysts reached up to 21.668 mmol g−1 and 29.179 mmol g−1 for 8 h in the presence of triethanolamine electron donor under visible light irradiation, which were about 11 and 15 times higher than that of m-CN/BP binary heterojunctions, 4 and 5 times higher than that of m-CN/BP/MoS2 ternary heterojunctions, respectively. Ni or Co co-catalysts enhanced charge separation and thus increasing the rate of H2 evolution owing to their suitable d-band levels. This present study supplies a strategy to design efficient photocatalysts for solar fuel production without using non-noble metal cocatalysts.

Phase-Engineered Robust Cocatalyst of NiFe Bicarbonate with Pt Dopant for Enhanced Photocatalytic Water Splitting.

Exploring efficient cocatalysts capable of accelerating surface catalytic reaction is of great significance for the development of solar-driven hydrogen production. Herein, on the basis of NiFe hydroxide, we developed a series of Pt doped NiFe-based cocatalysts to promote the photocatalytic hydrogen production of graphitic carbon nitride (g-C3 N4 ). We find that the Pt doping can trigger phase reconstruction of NiFe hydroxide and lead to the formation of NiFe bicarbonate, which displays higher catalytic activity toward hydrogen evolution reaction (HER). The Pt doped NiFe bicarbonate modified g-C3 N4 shows excellent photocatalytic activity with H2 evolution rate up to 100 μmol/h, which is more than 300 times that of pristine g-C3 N4 . The experimental and calculation results demonstrate that the greatly improved photocatalytic HER activity of g-C3 N4 is not only due to the efficient carrier separation, but also attributed to the accelerated HER kinetics. Our work may provide guidance for designing novel and superior photocatalysts.

Preparation of carbon nitride nanotubes with P-doping and their photocatalytic properties for hydrogen evolution

Various carbon nitride (C3N4) materials show great potential as an eco-friendly, visible-light-active photocatalyst for hydrogen evolution reaction (HER). In this work, a new route to produce one-dimensional (1D) P-doped carbon nitride nanotubes is developed via supramolecular self-assembly. The nanotubes are produced by thermal condensation of melamine and cyanuric acid. The addition of an ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) improves the uniformity of the nanotubes. It is revealed that the C3N4 nanotubes are formed by thermal condensation of rod-shaped intermediates. The nanotubes show an excellent photocatalytic HER activity under visible light irradiation and are a superior catalyst to 3D C3N4 samples. From thorough structural and photophysical characterizations, it is found that the nanotubes contain larger surface areas, more amine bridges, better crystallinity, and more visible-light-absorption ability than control samples. These structural features are reasons for the enhanced photocatalytic performance.

Facile Synthesis of Amorphous NiO/Reduced Graphene Oxide as a Cocatalyst for Enhanced Dye-Sensitized Photocatalytic H2 Evolution

It is still a challenge to develop efficient catalysts for hydrogen evolution reaction (HER) via a low-cost and simple method. Herein, we report an amorphous NiO/reduced graphene oxide (A-NG) composite as a cocatalyst for enhanced photocatalytic H2 evolution via dye sensitization. The A-NG composite is facilely fabricated by calcinating the NiCl2/GO precursor at a low temperature of 250 °C. The detailed characterizations show that amorphous NiO presents as tiny nanoparticles highly dispersed on graphene sheets, and nickel carbide is formed at the NiO/graphene interface, which demonstrates the strong interaction between Ni and the defective carbon of graphene. Compared with crystalline NiO/rGO (C-NG), the A-NG cocatalyst shows much enhanced dye-sensitized photocatalytic HER activity because the amorphous NiO nanoparticles can effectively adsorb the dye. As a result, highly dispersed amorphous NiO accelerates the photoinduced electron transfer from the excited dye to the cocatalyst, namely, the amorphous nickel carbide formed between NiO and rGO. This work provides a low-cost and simple method to develop efficient cocatalysts for photocatalytic H2 evolution.

Halogen–Hydrogen Bonding for the Synthesis of Efficient Polymeric Carbon‐Nitride Photocatalysts

Carbon nitride (CN) materials demonstrate great promise as photocatalysts for various reactions. However, synthesizing a CN with high dispersibility in water, large specific surface area, ordered morphology, and high catalytic activity remains a challenge. Melem (2,5,8‐triamino‐tri‐s‐triazine) has emerged as a monomer for the synthesis of CN materials owing to its high thermal stability, which favors controlled condensation over sublimation and decomposition at high temperatures. Herein, the synthesis of porous CN materials is shown with high dispersibility in water and excellent photocatalytic activity for the hydrogen evolution reaction (HER). To this end, various supramolecular assemblies are designed which are composed of melem combined with different hydrohalogenic acids as precursors of CNs. The results show that the HX (HX (aq), where X = Cl, Br, I) type directs the morphology, optical, and electronic properties of the resulting CN materials, particularly their surface area and photophysical properties. Moreover, the presence of HX results in a CN with a larger amount of free NH2 groups, which allow good dispersibility in water and act as linking groups to a photodeposited Pt cocatalyst. The elucidation of the optimum acid concentration and type leads to the synthesis of a CN with high and stable photocatalytic HER activity.

3D‐Printed Metal–Organic Framework‐Derived Composites for Enhanced Photocatalytic Hydrogen Generation

Photocatalytic Hydrogen Generation In article number 2200552, Mian Zahid Hussain, Yongde Xia, and co-workers present 3D printed monolith composites derived from Ti-metal organic framework (MOF) mixed with boehmite as promising photocatalysts, exhibiting a hydrogen evolution reaction (HER) performance 5 times higher than Ti-MOF-derived TiO2/C powder. Moreover, deposition of Pt onto 3D printed monolith by an atomic layer deposition approach provides additional active sites and further enhances the photocatalytic HER activity by 30%.

Well-Defined Ultrasmall V-NiP2 Nanoparticles Anchored g-C3N4 Nanosheets as Highly Efficient Visible-Light-Driven Photocatalysts for H2 Evolution

Exploring low-cost and highly active, cost-effective cocatalysts is of great significance to improve the hydrogen evolution performance of semiconductor photocatalysts. Herein, a novel ultrasmall V-doped NiP2 nanoparticle, as an efficient cocatalyst, is reported to largely upgrade the photocatalytic hydrogen evolution reaction (HER) of g-C3N4 nanosheets under visible-light irradiation. Experimental results demonstrate that V-NiP2 cocatalyst can enhance the visible-light absorption ability, facilitate the separation of photo-generated electron-hole pairs and boost the transfer ability of electrons of g-C3N4. Moreover, the V-NiP2/g-C3N4 hybrid exhibits prominent photocatalytic HER activity 17 times higher than the pristine g-C3N4 counterpart, even outperforming the 1 wt.% platinum-loaded g-C3N4. This work displays that noble-metal-free V-NiP2 cocatalyst can serve as a promising and efficient alternative to Pt for high-efficiency photocatalytic H2 evolution.

On the electronic properties and catalytic activity of MoS2–C3N4 materials prepared by one-pot reaction

MoS2–C3N4 composite materials with Mo content from 0.3 to 9 wt% have been prepared by means of one-pot synthesis from ammonium thiomolybdate (NH4)2MoS4 and urea-thiourea mixture. The solids were characterized by several physical techniques and tested in the thiophene hydrodesulfurization model reaction (HDS) and in photocatalytic hydrogen evolution reaction (PHER). Transmission electron microscopy (TEM) and X-ray absorption spectroscopy (XAS) show that even at the smallest Mo contents the solids contain individual MoS2 and C3N4 phases. As attested by powder X-ray diffraction (XRD), addition of (NH4)2MoS4 impacts the properties of obtained C3N4, probably at the growth stage, leading to more disordered carbon nitride phase. However, the materials demonstrate electronic properties close to a superposition of two separate MoS2 and C3N4 phases, as follows from the results of UV–visible diffuse reflectance spectroscopy (UV–vis DRS) combined with Ultraviolet and X-ray photoelectron spectroscopies (UPS, XPS). The band alignment diagram constructed from the UV–vis DRS, XPS and UPS data is of staggered type, the valence band edge of MoS2 being located above that of C3N4. Composite materials have high thiophene HDS activity, increasing in step with the Mo content, which proves fine dispersion of MoS2 phase and good availability of MoS2 edges to the reactants. By contrast, PHER activity first increases and then decreases with the Mo loading, reflecting on the competition between the ability of MoS2 to promote associative desorption of hydrogen and its role as a charge carriers recombination sink.

CdS/VS2 Heterostructured Nanoparticles as Efficient Visible‐Light‐Driven Photocatalysts for Boosting Hydrogen Evolution

AbstractThe development of highly active, cost‐effective hydrogen‐evolving photocatalysts is of great significance to alleviate the escalating environmental pollution and depleting fossil fuel sources. Herein, a novel CdS/VS2 heterostructured nanoparticle is successfully synthesized for the photocatalytic hydrogen evolution reaction (HER) under visible‐light irradiation via a facile hydrothermal route. Experimental results demonstrate that VS2 can facilitate the absorption of visible light, enhance the electron transfer rate, as well as inhibit the recombination of photogenerated electron‐hole pairs on CdS photocatalyst. Moreover, the optimal CdS/VS2 (0.2 wt.%) hybrid exhibits prominent photocatalytic HER activity 16 times higher than the pristine CdS counterpart, even outperforming the 1 wt.% platinum‐loaded CdS. This work injects new impetus to explore efficient noble‐metal‐free cocatalysts of CdS photocatalyst for high‐efficiency photocatalytic H2 evolution.

Size-dependent electron injection over sensitized semiconductor heterojunctions for enhanced photocatalytic hydrogen production

Mechanistic understanding of the effect of electron transfer rate across the semiconductor heterojunction interface on its photocatalytic activity remains elusive. Herein, a series of sensitized semiconductor heterojunctions consisting of monodisperse CdS quantum dots (QDs) with controllable sizes range of 2.2–6.5 nm and cadmium tetrakis(4-carboxyphenyl)porphyrin (Cd-TCPP) nanosheets are constructed through partial sulfidation strategy. The in situ resultant CdS/Cd-TCPP composites exhibit size-dependent photocatalytic hydrogen evolution reaction (HER) activity with the highest activity of 3150 μmol·h−1·g−1 obtained at a medium CdS QD size of 4.8 nm. It is demonstrated that the interfacial electron transfer rate and the corresponding photocatalytic HER activity can be regulated by tuning the CdS QD size that determines the conduction band position of CdS relative to Cd-TCPP. This work provides a new strategy that rationally controls the interfacial electron transfer rate for developing highly efficient photocatalysts.

Emerging Cocatalysts on g-C3 N4 for Photocatalytic Hydrogen Evolution.

Over the past few decades, graphitic carbon nitride (g-C3 N4 ) has arisen much attention as a promising candidate for photocatalytic hydrogen evolution reaction (HER) owing to its low cost and visible light response ability. However, the unsatisfied HER performance originated from the strong charge recombination of g-C3 N4 severely inhibits the further large-scale application of g-C3 N4 . In this case, the utilization of cocatalysts is a novel frontline in the g-C3 N4 -based photocatalytic systems due to the positive effects of cocatalysts on supressing charge carrier recombination, reducing the HER overpotential, and improving photocatalytic activity. This review summarizes some recent advances about the high-performance cocatalysts based on g-C3 N4 toward HER. Specifically, the functions, design principle, classification, modification strategies of cocatalysts, as well as their intrinsic mechanism for the enhanced photocatalytic HER activity are discussed here. Finally, the pivotal challenges and future developments of cocatalysts in the field of HER are further proposed.

Mixed-dimensional 1D CdS/2D MoSe2 heterostructures for high-performance photocatalytic hydrogen production

Rationally designing heterojunction photocatalysts with well-defined nanostructures and intimate interfacial contact is highly significant for improving the photocatalytic hydrogen evolution reaction (HER) activity. Here, we report on the fabrication of one-dimensional (1D) CdS/two-dimensional (2D) MoSe2 heterostructure for efficient photocatalytic hydrogen production. It is revealed that layered MoSe2 nanosheets are randomly anchored on CdS nanorods via an in-situ solvothermal process. When the loading content was kept at 10 wt%, the mix-dimensional nanohybrids exhibited a highly improved hydrogen-evolving rate up to 25.8 mmol g −1 h −1, which is 4 times higher than that of pristine CdS nanorods. The apparent quantum efficiency (AQE) of the optimized hybrid catalyst CM-10 is determined to be around 30% at 420 nm. The enhancement of photocatalytic HER activity can be attributed to the synergistic effect between 1D CdS nanorods and 2D MoSe2 nanosheets, which enables the accelerated electron-hole separation and more efficient interfacial charge transport. The findings in this study imply that, through morphology control and interfacial engineering, the efficiency and long-term stability of heterojunction photocatalysts toward hydrogen production from water splitting can be effectively tuned, providing new insights into the development of robust and high-performance visible light photocatalysts.

Integrating Mo2Bx (x = 1, 4) with CdS for efficient photocatalytic hydrogen production

Molybdenum based compounds, such as MoCx, MoSe2, MoS2 MoPx, MoOx and their derivatives, have been considered as the alternative catalysts for platinum (Pt) whether in electrocatalytic or photocatalytic hydrogen evolution reaction (HER). This means molybdenum based compounds have great application potential in solving the energy crisis and environmental pollution. Herein, for the first time, the unexplored Mo2Bx (x = 1 or 4) were investigated as the active components in a visible-light driven photocatalytic hydrogen production system. Experimental results demonstrate that they both exhibit excellent hydrogen evolution activities when combined with CdS or organic photosensitizers. Additionally, for the same kind of light-harvesting material, the photocatalytic HER activity of Mo2B4 is obviously better than that of Mo2B. This clearly indicates the photocatalytic activities of them are affected by the content of electron deficient atom boron (B) in Mo2Bx samples and exhibits a strong B dependence in photocatalytic HER. The reason for this B dependency is studied in detail by photo/electrochemical methods and optical characterizations in this work, where it is essentially caused by the difference in the electron transfer (ET) rates between light-harvesting material and Mo2Bx samples and just manifested as B dependency. Additionally, the relation between photocatalysis and electrocatalysis in HER is discussed.

Ruthenium nanoparticles supported on carbon-based nanoallotropes as co-catalyst to enhance the photocatalytic hydrogen evolution activity of carbon nitride

Development of competent and cost-effective materials for hydrogen evolution reaction (HER) has been attracting great attention since hydrogen is hailed as a promising environmentally friendly energy source to reduce the greenhouse emissions. Herein, Ru(0) nanoparticles (RuNPs) have been stabilized onto the surface of four different conducting carbon nanomaterials (CNMs) from 0D to 3D, such as 0D carbon nanohorns (CNH), 1D single-walled carbon nanotubes (CNTs), 2D reduced graphene oxide (rGO) and 3D graphite (GP), for their use in the photocatalytic HER. For this aim, the resulting RuNP@CNMs where physically mixed with mesoporous graphitic carbon nitride (mpg-CN) in an optimum composition ratio to maximize the photocatalytic HER activity. Notably, the resulting four hybrid RuNPs@CNM/mpg-CN materials showed an outstanding increase in the hydrogen evolution reaction (HER) when compared with the pristine mesoporous graphitic carbon nitride without co-catalyst. A comparison on the photocatalytic activity of the four hybrid RuNPs@CNMs physically mixed with mpg-CN and a deep study on the fate of the nanohybrids after catalysis are presented.