mainly responsible for excitation-dependent emission profiles in C-dots. The quantum yield (ɸ) of C-dots is also associated with the colour variations in C-dots. In
addition, the annihilation effect of C-dots is found to be minimum as compared to
conventionally used fluorophore for bioimaging applications (Huang et al. 2018;
Wang et al. 2019). C-dots have also displayed the single photon or two or multiphoton emission with down and up conversion fluorescence. The disordered band
due to sp
3 hybridized surface defects and G band due to the vibration of sp
2
hybridized carbon in C-dots have displayed characteristic peaks between 100 and
1580 cm
À1 in Raman spectra. The amount of graphitization and crystallization in
C-dots can be easily estimated from the ratio of the two peaks. The binding energy
peak profile for C1s and O1s is mainly observed at 287 and 534 eV in XPS spectra of
C-dots. Recently C-dots have found the potential application in the fabrication of
economically viable photosensitizers. The lower efficiency has mainly been tackled
during the synthesis of photosensitizer with high rate of stability. The
photoluminescence activity and photosensitization power can be easily modulated
by doping the particles with N atoms during the synthesis of C-dots (Zhang et al.
2018a, b; Li et al. 2018). The photo-oxidation property of C-dots can be easily
controlled via doping the C-dots. The response time of as prepared particles has been
found to be quite fast. These properties have further enhanced the water solubility of
C-dots and made them effective material in oxidase-mimicking nanozyme. These
enzymes have further been used for the photodynamic antimicrobial chemotherapeutic applications.
7.8
Dye Removal Activities of C-Dots for Waste Water Cleanup
The aspiration for the secure and pleasurable living standards by living individual
has produced unscrupulous discharge of harmful toxins including dye molecules into
water resources and causing considerable effect on the environment (Devi et al.
2019; Kaur et al. 2017; Zhou et al. 2019; Sharma et al. 2019a). The tremendous
growth in the textile industries, rapid urbanization and significant changes in the
living styles of human beings all over the world has also contributed to the deterioration of the environment. There is an urgent requirement to find new expertise for
handling environmental concerns especially water pollution. The extent of water
pollution is so hard that the existence of water resources is shrinking in an exponential manner. In this regard, C-dots have attained colossal interest among the
researchers for finding better alternatives for generating sustainable and economical
methods for dye removal from waste resources (Sharma et al. 2019a; Singh et al.
2019c; Natrajan et al. 2018; Asadian et al. 2019).
The application of luminescent C-dots in water cleanup has provided a boon for
researchers in the field of toxin sensing by using fluorescence technique (Sun and Lei
2017; Wei et al. 2014; Zhang et al. 2016). The use of renewable biomass as a starting
material for preparing C-dots has significantly reduced the cost of the process as
compared to the available synthetic methods for producing chemosensor. The
utilization of harmful and toxic chemicals during preparation of C-dots has also
7 Emerging Potential of Nano-Based Techniques for Dye Removal
179
addition, the annihilation effect of C-dots is found to be minimum as compared to
conventionally used fluorophore for bioimaging applications (Huang et al. 2018;
Wang et al. 2019). C-dots have also displayed the single photon or two or multiphoton emission with down and up conversion fluorescence. The disordered band
due to sp
3 hybridized surface defects and G band due to the vibration of sp
2
hybridized carbon in C-dots have displayed characteristic peaks between 100 and
1580 cm
À1 in Raman spectra. The amount of graphitization and crystallization in
C-dots can be easily estimated from the ratio of the two peaks. The binding energy
peak profile for C1s and O1s is mainly observed at 287 and 534 eV in XPS spectra of
C-dots. Recently C-dots have found the potential application in the fabrication of
economically viable photosensitizers. The lower efficiency has mainly been tackled
during the synthesis of photosensitizer with high rate of stability. The
photoluminescence activity and photosensitization power can be easily modulated
by doping the particles with N atoms during the synthesis of C-dots (Zhang et al.
2018a, b; Li et al. 2018). The photo-oxidation property of C-dots can be easily
controlled via doping the C-dots. The response time of as prepared particles has been
found to be quite fast. These properties have further enhanced the water solubility of
C-dots and made them effective material in oxidase-mimicking nanozyme. These
enzymes have further been used for the photodynamic antimicrobial chemotherapeutic applications.
7.8
Dye Removal Activities of C-Dots for Waste Water Cleanup
The aspiration for the secure and pleasurable living standards by living individual
has produced unscrupulous discharge of harmful toxins including dye molecules into
water resources and causing considerable effect on the environment (Devi et al.
2019; Kaur et al. 2017; Zhou et al. 2019; Sharma et al. 2019a). The tremendous
growth in the textile industries, rapid urbanization and significant changes in the
living styles of human beings all over the world has also contributed to the deterioration of the environment. There is an urgent requirement to find new expertise for
handling environmental concerns especially water pollution. The extent of water
pollution is so hard that the existence of water resources is shrinking in an exponential manner. In this regard, C-dots have attained colossal interest among the
researchers for finding better alternatives for generating sustainable and economical
methods for dye removal from waste resources (Sharma et al. 2019a; Singh et al.
2019c; Natrajan et al. 2018; Asadian et al. 2019).
The application of luminescent C-dots in water cleanup has provided a boon for
researchers in the field of toxin sensing by using fluorescence technique (Sun and Lei
2017; Wei et al. 2014; Zhang et al. 2016). The use of renewable biomass as a starting
material for preparing C-dots has significantly reduced the cost of the process as
compared to the available synthetic methods for producing chemosensor. The
utilization of harmful and toxic chemicals during preparation of C-dots has also
7 Emerging Potential of Nano-Based Techniques for Dye Removal
179