Energy
eV
meV
J
kJ/mol
Wavelength
nm
µm
cm⁻¹
Frequency / Time
THz
GHz
fs
ps
Temperature
K
°C
°F
k_BT (eV)
h = 4.1357 × 10⁻¹⁵ eV·s | c = 2.998 × 10¹⁷ nm/s
k_B = 8.617 × 10⁻⁵ eV/K | N_A = 6.022 × 10²³
k_B = 8.617 × 10⁻⁵ eV/K | N_A = 6.022 × 10²³
Electromagnetic Spectrum Locator
γ-ray
<0.01nm X-ray
0.01–10nm UV
10–400nm Vis
400–700nm NIR
700–2500nm IR
2.5–25µm THz
>25µm
<0.01nm X-ray
0.01–10nm UV
10–400nm Vis
400–700nm NIR
700–2500nm IR
2.5–25µm THz
>25µm
Current Values
—
eV
—
nm
—
THz
—
cm⁻¹
—
fs period
—
k_BT (eV)
Energy comparison — common spectroscopy wavelengths
Butler-Volmer Equation
The fundamental equation relating electrode current density to overpotential at an electrochemical interface.
j = j₀ · [ exp(αFη/RT)
− exp(−(1−α)Fη/RT) ]
F = 96485 C/mol | R = 8.314 J/mol·K
Limiting cases
Low η → linear: j ≈ j₀Fη/RT
High η (anodic): Tafel j ≈ j₀exp(αFη/RT)
High η (cathodic): j ≈ −j₀exp(−(1−α)Fη/RT)
0.01
j₀ (A/m²)
120
Anodic Tafel (mV/dec)
120
Cathodic Tafel (mV/dec)
—
R_ct (Ω·m²)
Current density j vs overpotential η
Tafel plot — log|j| vs η
About this tool
Interactive scientific computation platform built for the Bit2Catalyst Research Lab (B2C Lab). Designed for nano optics, electrochemistry, and advanced materials research.
Physical constants used
| Symbol | Quantity | Value |
|---|---|---|
| h | Planck constant | 4.13566743 × 10⁻¹⁵ eV·s |
| c | Speed of light | 2.99792458 × 10¹⁷ nm/s |
| k_B | Boltzmann constant | 8.617333 × 10⁻⁵ eV/K |
| N_A | Avogadro's number | 6.02214076 × 10²³ mol⁻¹ |
| F | Faraday constant | 96485 C/mol |
| R | Gas constant | 8.31446 J/mol·K |
| e | Elementary charge | 1.602176634 × 10⁻¹⁹ J/eV |