Facile Hydrothermally Synthesized a Novel CdS Nanoflower/Rutile-TiO₂ Nanorod Heterojunction Photoanode Used for Photoelectrocatalytic Hydrogen Generation

Abstract

With the application of ethylenediamine (EDA) as a solvent, a template, and co-ordination agents, novel photoanode architecture of the cadmium sulfide (CdS) nanoflower (NF)/rutile(R)-TiO 2 nanorod (NR) heterojunction is successfully synthesized using a facile two-step hydrothermal process. The optimized CdS (medium concentration; MC) NF/R-TiO 2 NR heterojunction exhibited a greatly enhanced visible-light photoelectrochemical (PEC) performance, whereby the highest photocurrent density of 3.23 mA cm −2 at 0.1 V versus Ag/AgCl and a photoconversion efficiency (PCE) of 0.46% were achieved under solar light irradiation. The optimal photocurrent density of the CdS (MC) NF/R-TiO 2 NR heterojunction, photoanode is 2.54 times (60.68%) higher than that of the pristine R-TiO 2 NR because of an effective light absorption, an appropriate band-edge position, and the charge separation. Furthermore, the open circuit voltage (V OC ) was shifted from −0.85 V to −1.34 V due to the grafting of the CdS NF onto the R-TiO 2 NR facet; this surface modification reveals the synergistic effect. The optimal CdS (MC) NF/R-TiO 2 NR heterojunction showed a PEC hydrogen (H 2 ) generation of 1007.98 μmol after 3 h. The design of the novel heterojunction photoanode that is proposed in the present strategy can shed light on the fabrication of new, cheap photocatalysts for an effective H 2 generation.

Constructing a Z-scheme Heterojunction of Egg-Like Core@shell CdS@TiO2 Photocatalyst via a Facile Reflux Method for Enhanced Photocatalytic Performance

“…It is notable that the UV–visible absorption spectra of CdS@TiO 2 presented a similar characteristic with CdS rather than TiO 2 , mainly because of the low content of TiO 2 , which demonstrated that CdS@TiO 2 heterostructure had been successfully constructed. Furthermore, the CdS@TiO 2 possesses a strong visible-light absorption band and shows an evident blue shift accompanied by an increasing loading amount of TiO 2 , which suggests that suitable TiO 2 content in CdS@TiO 2 composites is beneficial [ 26 ] and consistent with the TEM results. Therefore, a reasonably designed TiO 2 shell thickness is crucial for high performance photocatalytic materials.…”

Synthesis and Photocatalytic Activity of TiO2/CdS Nanocomposites with Co-Exposed Anatase Highly Reactive Facets

“…Therefore, it is necessary to design and synthesize TiO 2 -based semiconductor composite photocatalyst with exposed highly reactive facets to broaden its optical light absorption range and accelerate the separation of photogenerated electrons and holes, thus improving the photocatalytic efficiency [ 8 , 9 ]. To extend the light absorption range of TiO 2 to the visible region, numerous efforts have been made to combine TiO 2 with other semiconductors, such as Fe 2 O 3 [ 10 ], CdS [ 11 ], Cu 2 O [ 12 ], Ag 3 PO 4 [ 13 ], WO 3 [ 14 ], ZnS [ 15 ], and Bi 2 S 3 [ 16 ]. Among various inorganic semiconductors, cadmium sulfide (CdS) is considered to be one of the best cocatalyst candidates because of its appropriate bandgap (2.4 eV), low price and appropriate band edge position for photocatalytic redox reaction [ 4 , 17 ].…”

In Situ Integration of ReS2/Ni3S2 p-n Heterostructure for Enhanced Photoelectrocatalytic Performance

“…The higher C dl implies more accessible active sites for the ReS 2 /Ni 3 S 2 heterostructure. , Additionally, the electrochemical impedance spectroscopy (EIS) is measured to investigate the charge transport ability of the electrode. As shown in Figure b, the ReS 2 /Ni 3 S 2 heterostructure exhibits a smaller R ct than those of the Ni 3 S 2 /NF and ReS 2 –Ni 3 S 2 composites, suggesting the fastest charge transport. , …”