Zhuofeng Hu

0D/2D Heterojunctions of Vanadate Quantum Dots/Graphitic Carbon Nitride Nanosheets for Enhanced Visible-Light-Driven Photocatalysis

0D/2D heterojunctions, especially quantum dots (QDs)/nanosheets (NSs) have attracted significant attention for use of photoexcited electrons/holes due to their high charge mobility. Herein, unprecedent heterojunctions of vanadate (AgVO3 , BiVO4 , InVO4 and CuV2 O6 ) QDs/graphitic carbon nitride (g-C3 N4 ) NSs exhibiting multiple unique advances beyond traditional 0D/2D composites have been developed. The photoactive contribution, up-conversion absorption, and nitrogen coordinating sites of g-C3 N4 NSs, highly dispersed vanadate nanocrystals, as well as the strong coupling and band alignment between them lead to superior visible-light-driven photoelectrochemical (PEC) and photocatalytic performance, competing with the best reported photocatalysts. This work is expected to provide a new concept to construct multifunctional 0D/2D nanocomposites for a large variety of opto-electronic applications, not limited in photocatalysis.

Pt3Co-loaded CdS and TiO2 for photocatalytic hydrogen evolution from water

A new photocatalyst was prepared by loading 1 wt% of a platinum cobalt alloy on CdS via a simple polyol reduction method. XRD measurements confirmed the composition of the alloy as Pt3Co. Results from transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDX) measurements showed that Pt3Co nanoparticles with an average size of 4 nm were uniformly assembled on the surface of CdS. It was found that the activity of Pt3Co–CdS was approximately two times higher than that of Pt–CdS for photocatalytic H2 evolution. Photochemical measurements suggested that the high activity could be attributed to a better accumulation of photoexcited electrons and the higher conductivity of Pt3Co–CdS than that of Pt–CdS. The Pt3Co alloy cocatalyst was also loaded on TiO2, another widely used photocatalyst, and it also exhibited higher activity than pure Pt loaded on TiO2. This demonstrates the potential of Pt3Co as a universal cocatalyst.

An Elemental Phosphorus Photocatalyst with a Record High Hydrogen Evolution Efficiency

Semiconductive property of elementary substance is an interesting and attractive phenomenon. We obtain a breakthrough that fibrous phase red phosphorus, a recent discovered modification of red phosphorus by Ruck et al., can work as a semiconductor photocatalyst for visible-light-driven hydrogen (H2 ) evolution. Small sized fibrous phosphorus is obtained by 1) loading it on photoinactive SiO2 fibers or by 2) smashing it ultrasonically. They display the steady hydrogen evolution rates of 633 μmol h(-1)  g(-1) and 684 μmol h(-1)  g(-1) , respectively. These values are much higher than previous amorphous P (0.6 μmol h(-1)  g(-1) ) and Hittorf P (1.6 μmol h(-1)  g(-1) ). Moreover, they are the highest records in the family of elemental photocatalysts to date. This discovery is helpful for further understanding the semiconductive property of elementary substance. It is also favorable for the development of elemental photocatalysts.

Phosphorus containing materials for photocatalytic hydrogen evolution

Hydrogen from photocatalytic water splitting is a sustainable and renewable source of clean energy. The development of highly efficient photocatalysts is essential for the cost-effective and large-scale production of hydrogen. Effective photocatalysts made of earth abundant elements such as phosphorus have attracted great attention. The elemental red phosphorus by itself exhibits respectable photocatalytic activity, and some phosphorus compounds including phosphates and phosphides have also been found to be good photocatalysts. This timely review describes in detail all these P-containing species as well as P-doped systems. Their preparation, microstructure, optical and semiconductive properties are summarized thoroughly. Moreover, new findings about the relationship between the structure and activity are also discussed. Finally, inspired by the large amount of excellent examples, we have offered some perspectives for the future development of P-containing materials.

A nanostructured chromium(III) oxide/tungsten(VI) oxide p–n junction photoanode toward enhanced efficiency for water oxidation

A nanostructured chromium(III) oxide/tungsten(VI) oxide (Cr2O3/WO3) p–n junction photoanode is established here. It is prepared by depositing Cr2O3 nanoparticles onto WO3 nanosheet arrays. The formation of a p–n junction is confirmed by the Mott–Schottky plot and photocurrent measurements. Electrochemical and spectroscopic methods indicate that the recombination rate of photogenerated charges becomes lower in this photoanode. Consequently, its onset potential shifts negatively by about 0.1 V and photocurrent density increases from 0.7 to 1.8 mA cm−2 at 1.8 V vs. RHE. The incident photon-to-current efficiency (IPCE) also shows a one-fold improvement. In addition, the construction of the p–n junction leads to an increase of faradaic efficiency (holes to oxygen) from 73.9% to 92.0%, which is attributed to the suppression of side reactions in water oxidation. This work will provide new inspiration for improving the performance of WO3 and other photoanodes.

A metal-free composite photocatalyst of graphene quantum dots deposited on red phosphorus

A simple approach to enhance the photocatalytic activity of red phosphorus (P) was developed. A mechanical ball milling method was applied to reduce the size of red P and to deposit graphene quantum dots onto red P. The product was characterized by scanning electron microscopy, transmission electron microscopy, contact angle measurements, zeta-potential measurements, X-ray diffraction and UV-vis absorption spectroscopy. The product exhibited high visible-light-driven photocatalytic performance in the photodegradation of rhodamine B.